diff --git a/libs/yocto/yocto_sceneio.cpp b/libs/yocto/yocto_sceneio.cpp
index 36013a4c2..411d8b8ec 100644
--- a/libs/yocto/yocto_sceneio.cpp
+++ b/libs/yocto/yocto_sceneio.cpp
@@ -1951,18 +1951,15 @@ struct json_enum_trait<material_type> {
 };
 
 // Load a scene in the builtin JSON format.
-static void load_json_scene(
-    const string& filename, scene_data& scene, bool noparallel) {
+static void load_json_scene_version41(const string& filename, json_value& json,
+    scene_data& scene, bool noparallel) {
   // ends with
   auto ends_with = [](const string& str, const string& end) {
     if (str.size() < end.size()) return false;
     return str.substr(str.size() - end.size()) == end;
   };
 
-  // open file
-  auto json = load_json(filename);
-
-  // check vrsion
+  // check version
   if (!json.contains("asset") || !json.at("asset").contains("version"))
     return load_json_scene_version40(filename, json, scene, noparallel);
 
@@ -2002,43 +1999,9 @@ static void load_json_scene(
   auto material_map = unordered_map<string, int>{};
 
   // filenames
-  auto shape_datafiles   = vector<string>{};
-  auto texture_datafiles = vector<string>{};
-  auto subdiv_datafiles  = vector<string>{};
-
-  // // load json instance
-  // struct ply_instance {
-  //   vector<frame3f> frames = {};
-  // };
-  // using ply_instance_handle = int;
-  // auto ply_instances        = vector<ply_instance>{};
-  // auto ply_instances_names  = vector<string>{};
-  // auto ply_instance_map     = unordered_map<string, ply_instance_handle>{
-  //     {"", invalidid}};
-  // auto instance_ply = unordered_map<int, ply_instance_handle>{};
-  // auto get_ist      = [&scene, &ply_instances, &ply_instances_names,
-  //                    &ply_instance_map, &instance_ply](const json_value&
-  //                    json, const string& key, const instance_data& instance)
-  //                    {
-  //   auto name = json.value(key, string{});
-  //   if (name.empty()) return;
-  //   auto instance_id = (int)(&instance - scene.instances.data());
-  //   auto it          = ply_instance_map.find(name);
-  //   if (it != ply_instance_map.end()) {
-  //     instance_ply[instance_id] = it->second;
-  //   } else {
-  //     ply_instances_names.emplace_back(name);
-  //     ply_instances.emplace_back(ply_instance());
-  //     auto ply_instance_id      = (int)ply_instances.size() - 1;
-  //     ply_instance_map[name]    = ply_instance_id;
-  //     instance_ply[instance_id] = ply_instance_id;
-  //   }
-  // };
-  // auto get_ply_instance_name = [&ply_instances, &ply_instances_names](
-  //                                  const scene_data&   scene,
-  //                                  const ply_instance& instance) -> string {
-  //   return ply_instances_names[&instance - ply_instances.data()];
-  // };
+  auto shape_filenames   = vector<string>{};
+  auto texture_filenames = vector<string>{};
+  auto subdiv_filenames  = vector<string>{};
 
   // prepare data
   auto dirname = path_dirname(filename);
@@ -2080,11 +2043,11 @@ static void load_json_scene(
       auto& group = json.at("textures");
       scene.textures.reserve(group.size());
       scene.texture_names.reserve(group.size());
-      texture_datafiles.reserve(group.size());
+      texture_filenames.reserve(group.size());
       for (auto& [key, element] : group.items()) {
         [[maybe_unused]] auto& texture = scene.textures.emplace_back();
         scene.texture_names.push_back(key);
-        auto& datafile   = texture_datafiles.emplace_back();
+        auto& datafile   = texture_filenames.emplace_back();
         texture_map[key] = (int)scene.textures.size() - 1;
         if (element.is_string()) {
           auto filename = element.get<string>();
@@ -2132,11 +2095,11 @@ static void load_json_scene(
       auto& group = json.at("shapes");
       scene.shapes.reserve(group.size());
       scene.shape_names.reserve(group.size());
-      shape_datafiles.reserve(group.size());
+      shape_filenames.reserve(group.size());
       for (auto& [key, element] : group.items()) {
         [[maybe_unused]] auto& shape = scene.shapes.emplace_back();
         scene.shape_names.push_back(key);
-        auto& datafile = shape_datafiles.emplace_back();
+        auto& datafile = shape_filenames.emplace_back();
         shape_map[key] = (int)scene.shapes.size() - 1;
         if (element.is_string()) {
           auto filename = element.get<string>();
@@ -2154,11 +2117,11 @@ static void load_json_scene(
       auto& group = json.at("subdivs");
       scene.subdivs.reserve(group.size());
       scene.subdiv_names.reserve(group.size());
-      subdiv_datafiles.reserve(group.size());
+      subdiv_filenames.reserve(group.size());
       for (auto& [key, element] : group.items()) {
         auto& subdiv = scene.subdivs.emplace_back();
         scene.subdiv_names.emplace_back(key);
-        auto& datafile = subdiv_datafiles.emplace_back();
+        auto& datafile = subdiv_filenames.emplace_back();
         if (element.is_string()) {
           auto filename = element.get<string>();
           element       = load_json(path_join(dirname, "subdivs", filename));
@@ -2215,47 +2178,6 @@ static void load_json_scene(
         }
       }
     }
-    // if (json.contains("object_instances")) {
-    //   for (auto& [key, element] : json.at("object_instances").items()) {
-    //     auto& instance = ply_instances.emplace_back();
-    //     if (element.is_string()) {
-    //       auto filename = element.get<string>();
-    //       element       = load_json(path_join(dirname, "objects", filename));
-    //     }
-    //     get_opt(element, "frame", instance.frame);
-    //     get_rrf(element, "shape", instance.shape, shape_map);
-    //     get_rrf(element, "material", instance.material, material_map);
-    //     if (element.contains("lookat")) {
-    //       get_opt(element, "lookat", (mat3f&)instance.frame);
-    //       instance.frame = lookat_frame(
-    //           instance.frame.x, instance.frame.y, instance.frame.z, false);
-    //     }
-    //     if (element.contains("ply_instance")) {
-    //       get_ist(element, "instance", instance);
-    //     }
-    //   }
-    // }
-    // if (json.contains("objects")) {
-    //   for (auto& [key, element] : json.at("objects").items()) {
-    //     auto& instance = scene.instances.emplace_back();
-    //     scene.instance_names.emplace_back(key);
-    //     if (element.is_string()) {
-    //       auto filename = element.get<string>();
-    //       element       = load_json(path_join(dirname, "objects", filename));
-    //     }
-    //     get_opt(element, "frame", instance.frame);
-    //     get_rrf(element, "shape", instance.shape, shape_map);
-    //     get_rrf(element, "material", instance.material, material_map);
-    //     if (element.contains("lookat")) {
-    //       get_opt(element, "lookat", (mat3f&)instance.frame);
-    //       instance.frame = lookat_frame(
-    //           instance.frame.x, instance.frame.y, instance.frame.z, false);
-    //     }
-    //     if (element.contains("ply_instance")) {
-    //       get_ist(element, "instance", instance);
-    //     }
-    //   }
-    // }
   } catch (const json_error& error) {
     throw io_error::parse_error(
         filename, json_value::get_path(&json, error.where()));
@@ -2266,11 +2188,11 @@ static void load_json_scene(
   }
 
   // fix paths
-  for (auto& datafile : shape_datafiles)
+  for (auto& datafile : shape_filenames)
     datafile = path_join(dirname, "shapes", datafile);
-  for (auto& datafile : texture_datafiles)
+  for (auto& datafile : texture_filenames)
     datafile = path_join(dirname, "textures", datafile);
-  for (auto& datafile : subdiv_datafiles)
+  for (auto& datafile : subdiv_filenames)
     datafile = path_join(dirname, "subdivs", datafile);
 
   // load resources
@@ -2278,78 +2200,242 @@ static void load_json_scene(
     if (noparallel) {
       // load shapes
       for (auto idx : range(scene.shapes.size())) {
-        load_shape(shape_datafiles[idx], scene.shapes[idx], true);
+        load_shape(shape_filenames[idx], scene.shapes[idx], true);
       }
       // load subdivs
       for (auto idx : range(scene.subdivs.size())) {
-        load_subdiv(subdiv_datafiles[idx], scene.subdivs[idx]);
+        load_subdiv(subdiv_filenames[idx], scene.subdivs[idx]);
       }
       // load textures
       for (auto idx : range(scene.textures.size())) {
-        load_texture(texture_datafiles[idx], scene.textures[idx]);
+        load_texture(texture_filenames[idx], scene.textures[idx]);
       }
-      // load instances
-      // for (auto& ply_instance : ply_instances) {
-      //   auto path = find_path(
-      //       get_ply_instance_name(scene, ply_instance), "instances",
-      //       {".ply"});
-      //   load_instance(path_join(dirname, path), ply_instance.frames);
-      // }
     } else {
       // load shapes
       parallel_for(scene.shapes.size(), [&](size_t idx) {
-        load_shape(shape_datafiles[idx], scene.shapes[idx], true);
+        load_shape(shape_filenames[idx], scene.shapes[idx], true);
       });
       // load subdivs
       parallel_for(scene.subdivs.size(), [&](size_t idx) {
-        load_subdiv(subdiv_datafiles[idx], scene.subdivs[idx]);
+        load_subdiv(subdiv_filenames[idx], scene.subdivs[idx]);
       });
       // load textures
       parallel_for(scene.textures.size(), [&](size_t idx) {
-        load_texture(texture_datafiles[idx], scene.textures[idx]);
+        load_texture(texture_filenames[idx], scene.textures[idx]);
       });
-      // // load instances
-      // parallel_foreach(ply_instances, [&](auto& ply_instance) {
-      //   auto path = find_path(
-      //       get_ply_instance_name(scene, ply_instance), "instances",
-      //       {".ply"});
-      //   load_instance(path_join(dirname, path), ply_instance.frames);
-      // });
     }
   } catch (const io_error& exception) {
     throw io_error::dependent_error(filename, exception);
   }
 
-  // apply instances
-  // if (!ply_instances.empty()) {
-  //   auto instances      = scene.instances;
-  //   auto instance_names = scene.instance_names;
-  //   scene.instances.clear();
-  //   scene.instance_names.clear();
-  //   for (auto& instance : instances) {
-  //     auto it = instance_ply.find((int)(&instance - instances.data()));
-  //     if (it == instance_ply.end()) {
-  //       auto& ninstance = scene.instances.emplace_back();
-  //       scene.instance_names.emplace_back(
-  //           instance_names[&instance - instances.data()]);
-  //       ninstance.frame    = instance.frame;
-  //       ninstance.shape    = instance.shape;
-  //       ninstance.material = instance.material;
-  //     } else {
-  //       auto& ply_instance = ply_instances[it->second];
-  //       auto  instance_id  = 0;
-  //       for (auto& frame : ply_instance.frames) {
-  //         auto& ninstance = scene.instances.emplace_back();
-  //         scene.instance_names.emplace_back(
-  //             instance_names[&instance - instances.data()] + "_" +
-  //             std::to_string(instance_id++));
-  //         ninstance.frame    = frame * instance.frame;
-  //         ninstance.shape    = instance.shape;
-  //         ninstance.material = instance.material;
-  //       }
-  //     }
-  //   }
-  // }
+  // fix scene
+  add_missing_camera(scene);
+  add_missing_radius(scene);
+  trim_memory(scene);
+}
+
+// Load a scene in the builtin JSON format.
+static void load_json_scene(
+    const string& filename, scene_data& scene, bool noparallel) {
+  // open file
+  auto json = load_json(filename);
+
+  // check version
+  if (!json.contains("asset") || !json.at("asset").contains("version"))
+    return load_json_scene_version40(filename, json, scene, noparallel);
+  if (json.contains("asset") && json.at("asset").contains("version") &&
+      json.at("asset").at("version") == "4.1")
+    return load_json_scene_version41(filename, json, scene, noparallel);
+
+  // parse json value
+  auto get_opt = [](const json_value& json, const string& key, auto& value) {
+    value = json.value(key, value);
+  };
+  auto get_req = [](const json_value& json, const string& key, auto& value) {
+    try {
+      json.at(key).get(value);
+    } catch (const std::out_of_range&) {
+      throw json_error{"missing reference", &json};
+    }
+  };
+
+  // filenames
+  auto shape_filenames   = vector<string>{};
+  auto texture_filenames = vector<string>{};
+  auto subdiv_filenames  = vector<string>{};
+
+  // prepare data
+  auto dirname = path_dirname(filename);
+
+  // parsing values
+  try {
+    if (json.contains("asset")) {
+      auto& element = json.at("asset");
+      get_opt(element, "copyright", scene.copyright);
+      auto version = string{};
+      get_req(element, "version", version);
+      if (version != "4.2" && version != "5.0")
+        throw json_error("bad version", &element);
+    }
+    if (json.contains("cameras")) {
+      auto& group = json.at("cameras");
+      scene.cameras.reserve(group.size());
+      scene.camera_names.reserve(group.size());
+      for (auto& element : group) {
+        auto& camera = scene.cameras.emplace_back();
+        auto& name   = scene.camera_names.emplace_back();
+        get_opt(element, "name", name);
+        get_opt(element, "frame", camera.frame);
+        get_opt(element, "orthographic", camera.orthographic);
+        get_opt(element, "ortho", camera.orthographic);
+        get_opt(element, "lens", camera.lens);
+        get_opt(element, "aspect", camera.aspect);
+        get_opt(element, "film", camera.film);
+        get_opt(element, "focus", camera.focus);
+        get_opt(element, "aperture", camera.aperture);
+      }
+    }
+    if (json.contains("textures")) {
+      auto& group = json.at("textures");
+      scene.textures.reserve(group.size());
+      scene.texture_names.reserve(group.size());
+      texture_filenames.reserve(group.size());
+      for (auto& element : group) {
+        [[maybe_unused]] auto& texture = scene.textures.emplace_back();
+        auto&                  name    = scene.texture_names.emplace_back();
+        auto&                  uri     = texture_filenames.emplace_back();
+        get_opt(element, "name", name);
+        get_req(element, "uri", uri);
+      }
+    }
+    if (json.contains("materials")) {
+      auto& group = json.at("materials");
+      scene.materials.reserve(group.size());
+      scene.material_names.reserve(group.size());
+      for (auto& element : json.at("materials")) {
+        auto& material = scene.materials.emplace_back();
+        auto& name     = scene.material_names.emplace_back();
+        get_opt(element, "name", name);
+        get_opt(element, "type", material.type);
+        get_opt(element, "emission", material.emission);
+        get_opt(element, "color", material.color);
+        get_opt(element, "metallic", material.metallic);
+        get_opt(element, "roughness", material.roughness);
+        get_opt(element, "ior", material.ior);
+        get_opt(element, "trdepth", material.trdepth);
+        get_opt(element, "scattering", material.scattering);
+        get_opt(element, "scanisotropy", material.scanisotropy);
+        get_opt(element, "opacity", material.opacity);
+        get_opt(element, "emission_tex", material.emission_tex);
+        get_opt(element, "color_tex", material.color_tex);
+        get_opt(element, "roughness_tex", material.roughness_tex);
+        get_opt(element, "scattering_tex", material.scattering_tex);
+        get_opt(element, "normal_tex", material.normal_tex);
+      }
+    }
+    if (json.contains("shapes")) {
+      auto& group = json.at("shapes");
+      scene.shapes.reserve(group.size());
+      scene.shape_names.reserve(group.size());
+      shape_filenames.reserve(group.size());
+      for (auto& element : group) {
+        [[maybe_unused]] auto& shape = scene.shapes.emplace_back();
+        auto&                  name  = scene.shape_names.emplace_back();
+        auto&                  uri   = shape_filenames.emplace_back();
+        get_opt(element, "name", name);
+        get_req(element, "uri", uri);
+      }
+    }
+    if (json.contains("subdivs")) {
+      auto& group = json.at("subdivs");
+      scene.subdivs.reserve(group.size());
+      scene.subdiv_names.reserve(group.size());
+      subdiv_filenames.reserve(group.size());
+      for (auto& element : group) {
+        auto& subdiv = scene.subdivs.emplace_back();
+        auto& name   = scene.subdiv_names.emplace_back();
+        auto& uri    = subdiv_filenames.emplace_back();
+        get_opt(element, "name", name);
+        get_req(element, "uri", uri);
+        get_req(element, "shape", subdiv.shape);
+        get_opt(element, "subdivisions", subdiv.subdivisions);
+        get_opt(element, "catmullclark", subdiv.catmullclark);
+        get_opt(element, "smooth", subdiv.smooth);
+        get_opt(element, "displacement", subdiv.displacement);
+        get_opt(element, "displacement_tex", subdiv.displacement_tex);
+      }
+    }
+    if (json.contains("instances")) {
+      auto& group = json.at("instances");
+      scene.instances.reserve(group.size());
+      scene.instance_names.reserve(group.size());
+      for (auto element : group) {
+        auto& instance = scene.instances.emplace_back();
+        auto& name     = scene.instance_names.emplace_back();
+        get_opt(element, "name", name);
+        get_opt(element, "frame", instance.frame);
+        get_req(element, "shape", instance.shape);
+        get_req(element, "material", instance.material);
+      }
+    }
+    if (json.contains("environments")) {
+      auto& group = json.at("environments");
+      scene.instances.reserve(group.size());
+      scene.instance_names.reserve(group.size());
+      for (auto& element : group) {
+        auto& environment = scene.environments.emplace_back();
+        auto& name        = scene.environment_names.emplace_back();
+        get_opt(element, "name", name);
+        get_opt(element, "frame", environment.frame);
+        get_opt(element, "emission", environment.emission);
+        get_opt(element, "emission_tex", environment.emission_tex);
+      }
+    }
+  } catch (const json_error& error) {
+    throw io_error::parse_error(
+        filename, json_value::get_path(&json, error.where()));
+  } catch (...) {
+    throw io_error::parse_error(filename);
+  }
+
+  // load resources
+  try {
+    if (noparallel) {
+      // load shapes
+      for (auto idx : range(scene.shapes.size())) {
+        load_shape(
+            path_join(dirname, shape_filenames[idx]), scene.shapes[idx], true);
+      }
+      // load subdivs
+      for (auto idx : range(scene.subdivs.size())) {
+        load_subdiv(
+            path_join(dirname, subdiv_filenames[idx]), scene.subdivs[idx]);
+      }
+      // load textures
+      for (auto idx : range(scene.textures.size())) {
+        load_texture(
+            path_join(dirname, texture_filenames[idx]), scene.textures[idx]);
+      }
+    } else {
+      // load shapes
+      parallel_for(scene.shapes.size(), [&](size_t idx) {
+        load_shape(
+            path_join(dirname, shape_filenames[idx]), scene.shapes[idx], true);
+      });
+      // load subdivs
+      parallel_for(scene.subdivs.size(), [&](size_t idx) {
+        load_subdiv(
+            path_join(dirname, subdiv_filenames[idx]), scene.subdivs[idx]);
+      });
+      // load textures
+      parallel_for(scene.textures.size(), [&](size_t idx) {
+        load_texture(
+            path_join(dirname, texture_filenames[idx]), scene.textures[idx]);
+      });
+    }
+  } catch (const io_error& exception) {
+    throw io_error::dependent_error(filename, exception);
+  }
 
   // fix scene
   add_missing_camera(scene);
@@ -2366,10 +2452,14 @@ static void save_json_scene(
     item       = json_object{};
     return item;
   };
-  auto add_value = [](json_value& json, const string& name,
-                       const auto& value) -> json_value& {
+  auto add_array = [](json_value& json, const string& name) -> json_value& {
     auto& item = json.insert_back(name);
-    item       = value;
+    item       = json_array{};
+    return item;
+  };
+  auto append_object = [](json_value& json) -> json_value& {
+    auto& item = json.emplace_back();
+    item       = json_object{};
     return item;
   };
   auto set_opt = [](json_value& json, const string& name, const auto& value,
@@ -2383,43 +2473,54 @@ static void save_json_scene(
   auto set_orf = [](json_value& json, const string& name, int value,
                      const vector<string>& names) {
     if (value < 0) return;
-    json.insert_back(name) = names.at(value);
+    if (names.size() > value && names[value] != "") {
+      json.insert_back(name) = names.at(value);
+    } else {
+      json.insert_back(name) = value;
+    }
   };
   auto set_rrf = [](json_value& json, const string& name, int value,
                      const vector<string>& names) {
-    json.insert_back(name) = names.at(value);
+    if (names.size() > value && names[value] != "") {
+      json.insert_back(name) = names.at(value);
+    } else {
+      json.insert_back(name) = value;
+    }
   };
 
   // dirname
   auto dirname = path_dirname(filename);
 
   // names
-  auto camera_names  = make_names(scene.cameras, scene.camera_names, "camera");
-  auto texture_names = make_names(
-      scene.textures, scene.texture_names, "texture");
-  auto material_names = make_names(
-      scene.materials, scene.material_names, "material");
-  auto shape_names    = make_names(scene.shapes, scene.shape_names, "shape");
-  auto subdiv_names   = make_names(scene.subdivs, scene.subdiv_names, "subdiv");
-  auto instance_names = make_names(
-      scene.instances, scene.instance_names, "instance");
+  auto get_name = [](const vector<string>& names, size_t idx) -> string {
+    if (names.size() <= idx) return "";
+    return names[idx];
+  };
+  auto get_filename = [](const vector<string>& names, size_t idx,
+                          const string& basename,
+                          const string& extension) -> string {
+    if (names.size() <= idx) {
+      return basename + "s/" + names[idx] + extension;
+    } else {
+      return basename + "s/" + basename + extension;
+    }
+  };
 
   // filenames
-  auto shape_datafiles   = vector<string>(shape_names.size());
-  auto texture_datafiles = vector<string>(texture_names.size());
-  auto subdiv_datafiles  = vector<string>(subdiv_names.size());
-  for (auto idx : range(shape_datafiles.size())) {
-    shape_datafiles[idx] = path_join(
-        dirname, "shapes", shape_names[idx] + ".ply");
+  auto shape_filenames   = vector<string>(scene.shapes.size());
+  auto texture_filenames = vector<string>(scene.textures.size());
+  auto subdiv_filenames  = vector<string>(scene.subdivs.size());
+  for (auto idx : range(shape_filenames.size())) {
+    shape_filenames[idx] = get_filename(
+        scene.shape_names, idx, "shape", ".ply");
   }
-  for (auto idx : range(texture_datafiles.size())) {
-    texture_datafiles[idx] = path_join(dirname, "textures",
-        texture_names[idx] +
-            (scene.textures[idx].pixelsf.empty() ? ".png" : ".hdr"));
+  for (auto idx : range(texture_filenames.size())) {
+    texture_filenames[idx] = get_filename(scene.texture_names, idx, "texture",
+        (scene.textures[idx].pixelsf.empty() ? ".png" : ".hdr"));
   }
-  for (auto idx : range(subdiv_datafiles.size())) {
-    subdiv_datafiles[idx] = path_join(
-        dirname, "subdivs", subdiv_names[idx] + ".obj");
+  for (auto idx : range(subdiv_filenames.size())) {
+    subdiv_filenames[idx] = get_filename(
+        scene.subdiv_names, idx, "subdiv", ".obj");
   }
 
   // save json file
@@ -2432,15 +2533,16 @@ static void save_json_scene(
     set_opt(element, "copyright", scene.copyright, "");
     set_req(element, "generator",
         "Yocto/GL - https://github.com/xelatihy/yocto-gl");
-    set_req(element, "version", "4.1");
+    set_req(element, "version", "4.2");
   }
 
   if (!scene.cameras.empty()) {
     auto  default_ = camera_data{};
-    auto& group    = add_object(json, "cameras");
+    auto& group    = add_array(json, "cameras");
     group.reserve(scene.cameras.size());
     for (auto&& [idx, camera] : enumerate(scene.cameras)) {
-      auto& element = add_object(group, camera_names[idx]);
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.camera_names, idx), "");
       set_opt(element, "frame", camera.frame, default_.frame);
       set_opt(
           element, "orthographic", camera.orthographic, default_.orthographic);
@@ -2453,20 +2555,22 @@ static void save_json_scene(
   }
 
   if (!scene.textures.empty()) {
-    auto& group = add_object(json, "textures");
+    auto& group = add_array(json, "textures");
     group.reserve(scene.textures.size());
     for (auto&& [idx, texture] : enumerate(scene.textures)) {
-      add_value(group, texture_names[idx],
-          texture_names[idx] + (texture.pixelsf.empty() ? ".png" : ".hdr"));
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.texture_names, idx), "");
+      set_req(element, "uri", texture_filenames[idx]);
     }
   }
 
   if (!scene.materials.empty()) {
     auto  default_ = material_data{};
-    auto& group    = add_object(json, "materials");
+    auto& group    = add_array(json, "materials");
     group.reserve(scene.materials.size());
     for (auto&& [idx, material] : enumerate(scene.materials)) {
-      auto& element = add_object(group, material_names[idx]);
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.material_names, idx), "");
       set_opt(element, "type", material.type, default_.type);
       set_opt(element, "emission", material.emission, default_.emission);
       set_opt(element, "color", material.color, default_.color);
@@ -2478,12 +2582,14 @@ static void save_json_scene(
       set_opt(element, "scanisotropy", material.scanisotropy,
           default_.scanisotropy);
       set_opt(element, "opacity", material.opacity, default_.opacity);
-      set_orf(element, "emission_tex", material.emission_tex, texture_names);
-      set_orf(element, "color_tex", material.color_tex, texture_names);
-      set_orf(element, "roughness_tex", material.roughness_tex, texture_names);
       set_orf(
-          element, "scattering_tex", material.scattering_tex, texture_names);
-      set_orf(element, "normal_tex", material.normal_tex, texture_names);
+          element, "emission_tex", material.emission_tex, scene.texture_names);
+      set_orf(element, "color_tex", material.color_tex, scene.texture_names);
+      set_orf(element, "roughness_tex", material.roughness_tex,
+          scene.texture_names);
+      set_orf(element, "scattering_tex", material.scattering_tex,
+          scene.texture_names);
+      set_orf(element, "normal_tex", material.normal_tex, scene.texture_names);
     }
   }
 
@@ -2491,18 +2597,21 @@ static void save_json_scene(
     auto& group = add_object(json, "shapes");
     group.reserve(scene.shapes.size());
     for (auto&& [idx, shape] : enumerate(scene.shapes)) {
-      add_value(group, shape_names[idx], shape_names[idx] + ".ply");
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.shape_names, idx), "");
+      set_req(element, "uri", shape_filenames[idx]);
     }
   }
 
   if (!scene.subdivs.empty()) {
     auto  default_ = subdiv_data{};
-    auto& group    = add_object(json, "subdivs");
+    auto& group    = add_array(json, "subdivs");
     group.reserve(scene.subdivs.size());
     for (auto&& [idx, subdiv] : enumerate(scene.subdivs)) {
-      auto& element = add_object(group, subdiv_names[idx]);
-      set_rrf(element, "shape", subdiv.shape, shape_names);
-      set_req(element, "datafile", subdiv_names[idx] + ".obj");
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.subdiv_names, idx), "");
+      set_rrf(element, "shape", subdiv.shape, scene.shape_names);
+      set_req(element, "uri", subdiv_filenames[idx]);
       set_opt(
           element, "subdivisions", subdiv.subdivisions, default_.subdivisions);
       set_opt(
@@ -2517,26 +2626,28 @@ static void save_json_scene(
 
   if (!scene.instances.empty()) {
     auto  default_ = instance_data{};
-    auto& group    = add_object(json, "instances");
+    auto& group    = add_array(json, "instances");
     group.reserve(scene.instances.size());
-    for (auto& instance : scene.instances) {
-      auto& element = add_object(group, get_instance_name(scene, instance));
+    for (auto&& [idx, instance] : enumerate(scene.instances)) {
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.instance_names, idx), "");
       set_opt(element, "frame", instance.frame, default_.frame);
-      set_rrf(element, "shape", instance.shape, shape_names);
-      set_rrf(element, "material", instance.material, material_names);
+      set_rrf(element, "shape", instance.shape, scene.shape_names);
+      set_rrf(element, "material", instance.material, scene.material_names);
     }
   }
 
   if (!scene.environments.empty()) {
     auto  default_ = environment_data{};
-    auto& group    = add_object(json, "environments");
+    auto& group    = add_array(json, "environments");
     group.reserve(scene.environments.size());
-    for (auto& environment : scene.environments) {
-      auto& element = add_object(
-          group, get_environment_name(scene, environment));
+    for (auto&& [idx, environment] : enumerate(scene.environments)) {
+      auto& element = append_object(group);
+      set_opt(element, "name", get_name(scene.environment_names, idx), "");
       set_opt(element, "frame", environment.frame, default_.frame);
       set_opt(element, "emission", environment.emission, default_.emission);
-      set_orf(element, "emission_tex", environment.emission_tex, texture_names);
+      set_orf(element, "emission_tex", environment.emission_tex,
+          scene.texture_names);
     }
   }
 
@@ -2548,28 +2659,34 @@ static void save_json_scene(
     if (noparallel) {
       // save shapes
       for (auto idx : range(scene.shapes.size())) {
-        save_shape(shape_datafiles[idx], scene.shapes[idx], true);
+        save_shape(
+            path_join(dirname, shape_filenames[idx]), scene.shapes[idx], true);
       }
       // save subdiv
       for (auto idx : range(scene.subdivs.size())) {
-        save_subdiv(subdiv_datafiles[idx], scene.subdivs[idx]);
+        save_subdiv(
+            path_join(dirname, subdiv_filenames[idx]), scene.subdivs[idx]);
       }
       // save textures
       for (auto idx : range(scene.textures.size())) {
-        save_texture(texture_datafiles[idx], scene.textures[idx]);
+        save_texture(
+            path_join(dirname, texture_filenames[idx]), scene.textures[idx]);
       }
     } else {
       // save shapes
       parallel_for(scene.shapes.size(), [&](auto idx) {
-        save_shape(shape_datafiles[idx], scene.shapes[idx], true);
+        save_shape(
+            path_join(dirname, shape_filenames[idx]), scene.shapes[idx], true);
       });
       // save subdivs
       parallel_for(scene.subdivs.size(), [&](auto idx) {
-        save_subdiv(subdiv_datafiles[idx], scene.subdivs[idx]);
+        save_subdiv(
+            path_join(dirname, subdiv_filenames[idx]), scene.subdivs[idx]);
       });
       // save textures
       parallel_for(scene.textures.size(), [&](auto idx) {
-        save_texture(texture_datafiles[idx], scene.textures[idx]);
+        save_texture(
+            path_join(dirname, texture_filenames[idx]), scene.textures[idx]);
       });
     }
   } catch (const io_error& exception) {
diff --git a/scripts/scene.schema.json b/scripts/scene.schema.json
index f176642de..f8a652462 100644
--- a/scripts/scene.schema.json
+++ b/scripts/scene.schema.json
@@ -22,18 +22,19 @@
     "cameras": {
       "description": "Scene cameras",
       "type": "object",
-      "additionalProperties": {
+      "items": {
         "description": "Camera",
         "type": "object",
         "properties": {
+          "name": {
+            "description": "Name",
+            "type": "string"
+          },
           "frame": {
             "description": "Frame",
             "type": "array",
             "items": {
-              "type": "array",
-              "items": {
-                "type": "number"
-              }
+              "type": "number"
             }
           },
           "lens": {
@@ -61,11 +62,15 @@
     },
     "environments": {
       "description": "Scene environments",
-      "type": "object",
-      "additionalProperties": {
+      "type": "array",
+      "items": {
         "description": "Environment",
         "type": "object",
         "properties": {
+          "name": {
+            "description": "Name",
+            "type": "string"
+          },
           "frame": {
             "description": "Frame",
             "type": "array",
@@ -89,11 +94,15 @@
     },
     "materials": {
       "description": "Scene materials",
-      "type": "object",
-      "additionalProperties": {
+      "type": "array",
+      "items": {
         "description": "Object",
         "type": "object",
         "properties": {
+          "name": {
+            "description": "Name",
+            "type": "string"
+          },
           "emission": {
             "description": "Emission",
             "type": "array",
diff --git a/scripts/upgrade-scenes.py b/scripts/upgrade-scenes-41.py
similarity index 100%
rename from scripts/upgrade-scenes.py
rename to scripts/upgrade-scenes-41.py
diff --git a/scripts/upgrade-scenes-42.py b/scripts/upgrade-scenes-42.py
new file mode 100755
index 000000000..4786c11bc
--- /dev/null
+++ b/scripts/upgrade-scenes-42.py
@@ -0,0 +1,47 @@
+#! /usr/bin/env python3 -B
+
+import json, argparse
+from typing import OrderedDict
+
+def upgrade(filename, remove_names):
+  with open(filename) as f:
+    scene = json.load(f, object_pairs_hook=OrderedDict)
+    if scene['asset']['version'] == "4.2": return
+    if scene['asset']['version'] != "4.1": return
+    shape_map = { name: id for id, name in enumerate(scene['shapes'].keys()) } if 'shapes' in scene else {}
+    texture_map = { name: id for id, name in enumerate(scene['textures'].keys()) } if 'textures' in scene else {}
+    material_map = { name: id for id, name in enumerate(scene['materials'].keys()) } if 'materials' in scene else {}
+    nscene = OrderedDict()
+    nscene['asset'] = scene['asset']
+    nscene['asset']['version'] = "4.2"
+    for groupname in ['cameras', 'environments', 'textures', 'materials', 'shapes', 'subdivs', 'instances']:
+      if groupname not in scene: continue
+      nscene[groupname] = []
+      for name, item in scene[groupname].items():
+        nitem = OrderedDict()
+        nscene[groupname].append(nitem)
+        if not remove_names: nitem['name'] = name
+        if groupname in ['textures', 'shapes']:
+          nitem['uri'] = groupname + "/" + item
+        else:
+          nitem.update(item)
+        for key, value in nitem.items():
+          if key.endswith('_tex'): nitem[key] = texture_map[value]
+          if key == 'shape': nitem[key] = shape_map[value]
+          if key == 'material': nitem[key] = material_map[value]
+          if key == 'frame' and isinstance(value[0], list):
+            nitem[key] = value[0] + value[1] + value[2] + value[3]
+        if 'datafile' in nitem:
+          nitem['uri'] = item['datafile']
+          del item['datafile']
+  with open(filename, 'w') as f:
+    json.dump(nscene, f, indent=2)
+
+parser = argparse.ArgumentParser(description='Upgrades scene.')
+parser.add_argument('scenes', type=str, nargs='+')
+parser.add_argument('--remove-names', action='store_true', default=False)
+args = parser.parse_args()
+
+for filename in args.scenes:
+  print(filename)
+  upgrade(filename, args.remove_names)
diff --git a/tests/arealights1/arealights1.json b/tests/arealights1/arealights1.json
index 6afe68a5c..fb7a4a1e2 100644
--- a/tests/arealights1/arealights1.json
+++ b/tests/arealights1/arealights1.json
@@ -2,200 +2,234 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, -0.3511234223842621],
-        [0.0, 0.3511234223842621, 0.936329185962677],
-        [0.0, 0.574999988079071, 1.399999976158142]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, 0.3511234223842621],
-        [0.0, 0.3511234223842621, -0.936329185962677],
-        [0.0, 0.574999988079071, -1.399999976158142]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "textures": [
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 0
     },
-    "arealight1": {
+    {
+      "name": "arealight1",
       "emission": [20.0, 20.0, 20.0]
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "emission": [20.0, 20.0, 20.0]
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 1
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071]
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "bunny": "bunny.ply",
-    "sphere": "sphere.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
-    },
-    "arealight1": {
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "arealight1",
       "frame": [
-        [0.8944271802902222, -0.0, 0.4472135901451111],
-        [0.27562475204467773, 0.7874992489814758, -0.5512495040893555],
-        [-0.3521803617477417, 0.6163156628608704, 0.7043607234954834],
-        [-0.4000000059604645, 0.800000011920929, 0.800000011920929]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 1,
+      "material": 1
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [0.8944271802902222, 0.0, -0.4472135901451111],
-        [-0.27562475204467773, 0.7874992489814758, -0.5512495040893555],
-        [0.3521803617477417, 0.6163156628608704, 0.7043607234954834],
-        [0.4000000059604645, 0.800000011920929, 0.800000011920929]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
+      "shape": 2,
+      "material": 2
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-uvgrid"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-sharp"
+      "shape": 4,
+      "material": 4
     },
-    "bunny-metal-rough": {
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
+    {
+      "name": "bunny-metal-rough",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough"
+      "shape": 4,
+      "material": 6
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-sharp"
+      "shape": 3,
+      "material": 7
     }
-  }
+  ]
 }
diff --git a/tests/cornellbox/cornellbox.json b/tests/cornellbox/cornellbox.json
index 460be3b1e..e8e97ffd3 100644
--- a/tests/cornellbox/cornellbox.json
+++ b/tests/cornellbox/cornellbox.json
@@ -1,90 +1,129 @@
 {
   "asset": {
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "camera1": {
+  "cameras": [
+    {
+      "name": "camera1",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.0, 1.0, 3.9000000953674316 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0,
+        3.9000000953674316
       ],
       "lens": 0.03500000014901161,
       "aspect": 1.0,
       "film": 0.024000000208616257,
       "focus": 3.9000000953674316
     }
-  },
-  "materials": {
-    "backwall": {
-      "color": [ 0.7250000238418579, 0.7099999785423279, 0.6800000071525574 ]
+  ],
+  "materials": [
+    {
+      "name": "backwall",
+      "color": [0.7250000238418579, 0.7099999785423279, 0.6800000071525574]
     },
-    "ceiling": {
-      "color": [ 0.7250000238418579, 0.7099999785423279, 0.6800000071525574 ]
+    {
+      "name": "ceiling",
+      "color": [0.7250000238418579, 0.7099999785423279, 0.6800000071525574]
     },
-    "floor": {
-      "color": [ 0.7250000238418579, 0.7099999785423279, 0.6800000071525574 ]
+    {
+      "name": "floor",
+      "color": [0.7250000238418579, 0.7099999785423279, 0.6800000071525574]
     },
-    "leftwall": {
-      "color": [ 0.6299999952316284, 0.06499999761581421, 0.05000000074505806 ]
+    {
+      "name": "leftwall",
+      "color": [0.6299999952316284, 0.06499999761581421, 0.05000000074505806]
     },
-    "light": {
-      "emission": [ 17.0, 12.0, 4.0 ]
+    {
+      "name": "light",
+      "emission": [17.0, 12.0, 4.0]
     },
-    "rightwall": {
-      "color": [ 0.14000000059604645, 0.44999998807907104, 0.09000000357627869 ]
+    {
+      "name": "rightwall",
+      "color": [0.14000000059604645, 0.44999998807907104, 0.09000000357627869]
     },
-    "shortbox": {
-      "color": [ 0.7250000238418579, 0.7099999785423279, 0.6800000071525574 ]
+    {
+      "name": "shortbox",
+      "color": [0.7250000238418579, 0.7099999785423279, 0.6800000071525574]
     },
-    "tallbox": {
-      "color": [ 0.7250000238418579, 0.7099999785423279, 0.6800000071525574 ]
+    {
+      "name": "tallbox",
+      "color": [0.7250000238418579, 0.7099999785423279, 0.6800000071525574]
     }
-  },
-  "shapes": {
-    "backwall": "backwall.ply",
-    "ceiling": "ceiling.ply",
-    "floor": "floor.ply",
-    "leftwall": "leftwall.ply",
-    "light": "light.ply",
-    "rightwall": "rightwall.ply",
-    "shortbox": "shortbox.ply",
-    "tallbox": "tallbox.ply"
-  },
-  "instances": {
-    "backwall": {
-      "shape": "backwall",
-      "material": "backwall"
-    },
-    "ceiling": {
-      "shape": "ceiling",
-      "material": "ceiling"
-    },
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
-    },
-    "leftwall": {
-      "shape": "leftwall",
-      "material": "leftwall"
-    },
-    "light": {
-      "shape": "light",
-      "material": "light"
-    },
-    "rightwall": {
-      "shape": "rightwall",
-      "material": "rightwall"
-    },
-    "shortbox": {
-      "shape": "shortbox",
-      "material": "shortbox"
-    },
-    "tallbox": {
-      "shape": "tallbox",
-      "material": "tallbox"
+  ],
+  "shapes": [
+    {
+      "name": "backwall",
+      "uri": "shapes/backwall.ply"
+    },
+    {
+      "name": "ceiling",
+      "uri": "shapes/ceiling.ply"
+    },
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "leftwall",
+      "uri": "shapes/leftwall.ply"
+    },
+    {
+      "name": "light",
+      "uri": "shapes/light.ply"
+    },
+    {
+      "name": "rightwall",
+      "uri": "shapes/rightwall.ply"
+    },
+    {
+      "name": "shortbox",
+      "uri": "shapes/shortbox.ply"
+    },
+    {
+      "name": "tallbox",
+      "uri": "shapes/tallbox.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "backwall",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "ceiling",
+      "shape": 1,
+      "material": 1
+    },
+    {
+      "name": "floor",
+      "shape": 2,
+      "material": 2
+    },
+    {
+      "name": "leftwall",
+      "shape": 3,
+      "material": 3
+    },
+    {
+      "name": "light",
+      "shape": 4,
+      "material": 4
+    },
+    {
+      "name": "rightwall",
+      "shape": 5,
+      "material": 5
+    },
+    {
+      "name": "shortbox",
+      "shape": 6,
+      "material": 6
+    },
+    {
+      "name": "tallbox",
+      "shape": 7,
+      "material": 7
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/environments1/environments1.json b/tests/environments1/environments1.json
index cfc000105..c65582eef 100644
--- a/tests/environments1/environments1.json
+++ b/tests/environments1/environments1.json
@@ -2,179 +2,207 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, -0.3511234223842621],
-        [0.0, 0.3511234223842621, 0.936329185962677],
-        [0.0, 0.574999988079071, 1.399999976158142]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, 0.3511234223842621],
-        [0.0, 0.3511234223842621, -0.936329185962677],
-        [0.0, 0.574999988079071, -1.399999976158142]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sunsky": "sunsky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sunsky",
+      "emission": [1.0, 1.0, 1.0],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sunsky",
+      "uri": "textures/sunsky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071]
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "bunny": "bunny.ply",
-    "sphere": "sphere.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
-    },
-    "bunny-uvgrid": {
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "bunny-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-uvgrid"
+      "shape": 1,
+      "material": 1
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-sharp"
+      "shape": 2,
+      "material": 2
     },
-    "bunny-metal-rough": {
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
+    {
+      "name": "bunny-metal-rough",
+      "shape": 1,
+      "material": 3
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough"
+      "shape": 2,
+      "material": 4
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-sharp"
-    }
-  },
-  "environments": {
-    "sunsky": {
-      "emission": [1.0, 1.0, 1.0],
-      "emission_tex": "sunsky"
+      "shape": 1,
+      "material": 5
     }
-  }
+  ]
 }
diff --git a/tests/environments2/environments2.json b/tests/environments2/environments2.json
index ebb669b60..05332c567 100644
--- a/tests/environments2/environments2.json
+++ b/tests/environments2/environments2.json
@@ -2,179 +2,207 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, -0.3511234223842621],
-        [0.0, 0.3511234223842621, 0.936329185962677],
-        [0.0, 0.574999988079071, 1.399999976158142]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, 0.3511234223842621],
-        [0.0, 0.3511234223842621, -0.936329185962677],
-        [0.0, 0.574999988079071, -1.399999976158142]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [1.0, 1.0, 1.0],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071]
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "bunny": "bunny.ply",
-    "sphere": "sphere.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
-    },
-    "bunny-uvgrid": {
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "bunny-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-uvgrid"
+      "shape": 1,
+      "material": 1
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-sharp"
+      "shape": 2,
+      "material": 2
     },
-    "bunny-metal-rough": {
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
+    {
+      "name": "bunny-metal-rough",
+      "shape": 1,
+      "material": 3
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough"
+      "shape": 2,
+      "material": 4
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-sharp"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [1.0, 1.0, 1.0],
-      "emission_tex": "sky"
+      "shape": 1,
+      "material": 5
     }
-  }
+  ]
 }
diff --git a/tests/features1/features1.json b/tests/features1/features1.json
index d995b01c3..498b1062a 100644
--- a/tests/features1/features1.json
+++ b/tests/features1/features1.json
@@ -2,211 +2,252 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, -0.3511234223842621],
-        [0.0, 0.3511234223842621, 0.936329185962677],
-        [0.0, 0.574999988079071, 1.399999976158142]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, 0.3511234223842621],
-        [0.0, 0.3511234223842621, -0.936329185962677],
-        [0.0, 0.574999988079071, -1.399999976158142]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png",
-    "bumps-normal": "bumps-normal.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    },
+    {
+      "name": "bumps-normal",
+      "uri": "textures/bumps-normal.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "bunny-uvgrid-coated": {
+    {
+      "name": "bunny-uvgrid-coated",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.20000000298023224,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "bunny-volume-jade": {
+    {
+      "name": "bunny-volume-jade",
       "type": "refractive",
       "color": [0.5, 0.5, 0.5],
       "scattering": [
         0.30000001192092896, 0.6000000238418579, 0.30000001192092896
       ]
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "sphere-volume-glass": {
+    {
+      "name": "sphere-volume-glass",
       "type": "refractive",
       "color": [1.0, 0.5, 0.5]
     },
-    "sphere-plastic-rough-bumped": {
+    {
+      "name": "sphere-plastic-rough-bumped",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224,
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+      "normal_tex": 3
     },
-    "arealight1": {
+    {
+      "name": "arealight1",
       "emission": [20.0, 20.0, 20.0]
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "emission": [20.0, 20.0, 20.0]
     }
-  },
-  "shapes": {
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-    "bunny": "bunny.ply",
-    "sphere": "sphere.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
-    },
-    "bunny-uvgrid-coated": {
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
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       "frame": [
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-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
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+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-uvgrid-coated"
+      "shape": 1,
+      "material": 1
     },
-    "bunny-volume-jade": {
-      "shape": "bunny",
-      "material": "bunny-volume-jade"
+    {
+      "name": "bunny-volume-jade",
+      "shape": 1,
+      "material": 2
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
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+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
+      "shape": 1,
+      "material": 3
     },
-    "sphere-volume-glass": {
+    {
+      "name": "sphere-volume-glass",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
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+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-volume-glass"
+      "shape": 2,
+      "material": 4
     },
-    "sphere-plastic-rough-bumped": {
+    {
+      "name": "sphere-plastic-rough-bumped",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
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+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough-bumped"
+      "shape": 2,
+      "material": 5
     },
-    "arealight1": {
+    {
+      "name": "arealight1",
       "frame": [
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+        0.800000011920929, 0.800000011920929
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-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 3,
+      "material": 6
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [0.8944271802902222, 0.0, -0.4472135901451111],
-        [-0.27562475204467773, 0.7874992489814758, -0.5512495040893555],
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+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
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-      "shape": "arealight2",
-      "material": "arealight2"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [0.5, 0.5, 0.5],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 7
     }
-  }
+  ]
 }
diff --git a/tests/features2/features2.json b/tests/features2/features2.json
index f3719bc32..2f2f78300 100644
--- a/tests/features2/features2.json
+++ b/tests/features2/features2.json
@@ -2,238 +2,297 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
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-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
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       "focus": 1.2168092727661133
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       "frame": [
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-        [ 0.0, 0.936329185962677, -0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, 0.936329185962677 ],
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+        1.399999976158142
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       "aspect": 3.0,
       "focus": 1.4952006340026855
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-        [ 0.0, 0.936329185962677, 0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, -0.936329185962677 ],
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       "focus": 1.4952006340026855
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       "focus": 1.2168092727661133
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-    "perspective-dof": {
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       "frame": [
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-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
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       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
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-    "orthographic-sharp": {
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       "frame": [
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       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
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-    "orthographic-dof": {
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-  "materials": {
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     },
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+    {
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+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    },
+    {
+      "name": "bumps-displacement",
+      "uri": "textures/bumps-displacement.png"
+    }
+  ],
+  "materials": [
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+    {
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-    "sphere-uvgrid": {
+    {
+      "name": "arealight2",
+      "emission": [20.0, 20.0, 20.0]
+    },
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       "roughness": 0.10000000149011612,
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+      "color_tex": 2
     },
-    "suzanne-subdiv-plastic-rough": {
+    {
+      "name": "suzanne-subdiv-plastic-rough",
       "type": "glossy",
-      "color": [ 0.5, 0.699999988079071, 0.5 ],
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     },
-    "hairball1-hair": {
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+    {
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+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "sphere-displaced-plastic-rough": {
+    {
+      "name": "sphere-displaced-plastic-rough",
       "type": "glossy",
-      "color": [ 0.5, 0.699999988079071, 0.5 ],
+      "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "cube-uvgrid": {
+    {
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       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
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+      "color_tex": 2
     },
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+    {
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+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
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-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "sphere": "sphere.ply",
-    "suzanne-subdiv": "suzanne-subdiv.ply",
-    "hairball1": "hairball1.ply",
-    "sphere-displaced": "sphere-displaced.ply",
-    "cube": "cube.ply",
-    "hairballi": "hairballi.ply"
-  },
-  "subdivs": {
-    "suzanne-subdiv": {
-      "shape": "suzanne-subdiv",
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "suzanne-subdiv",
+      "uri": "shapes/suzanne-subdiv.ply"
+    },
+    {
+      "name": "hairball1",
+      "uri": "shapes/hairball1.ply"
+    },
+    {
+      "name": "sphere-displaced",
+      "uri": "shapes/sphere-displaced.ply"
+    },
+    {
+      "name": "cube",
+      "uri": "shapes/cube.ply"
+    },
+    {
+      "name": "hairballi",
+      "uri": "shapes/hairballi.ply"
+    }
+  ],
+  "subdivs": [
+    {
+      "name": "suzanne-subdiv",
+      "shape": 4,
       "datafile": "suzanne-subdiv.obj",
       "subdivisions": 2,
       "catmullclark": true,
-      "smooth": true
+      "smooth": true,
+      "uri": "suzanne-subdiv.obj"
     },
-    "sphere-displaced": {
-      "shape": "sphere-displaced",
+    {
+      "name": "sphere-displaced",
+      "shape": 6,
       "datafile": "sphere-displaced.obj",
       "catmullclark": true,
       "smooth": true,
       "displacement": 0.02500000037252903,
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+      "displacement_tex": 3,
+      "uri": "sphere-displaced.obj"
     }
-  },
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-      "material": "floor"
+  ],
+  "instances": [
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       "frame": [
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+      "shape": 3,
+      "material": 3
     },
-    "suzanne-subdiv-plastic-rough": {
+    {
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       "frame": [
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-        [ 0.0, 1.0, 0.0 ],
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+        0.0
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+      "shape": 4,
+      "material": 4
     },
-    "hairball1-hair": {
-      "shape": "hairball1",
-      "material": "hairball1-hair"
+    {
+      "name": "hairball1-hair",
+      "shape": 5,
+      "material": 5
     },
-    "sphere-displaced-plastic-rough": {
+    {
+      "name": "sphere-displaced-plastic-rough",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere-displaced",
-      "material": "sphere-displaced-plastic-rough"
+      "shape": 6,
+      "material": 6
     },
-    "cube-uvgrid": {
+    {
+      "name": "cube-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "cube",
-      "material": "cube-uvgrid"
+      "shape": 7,
+      "material": 7
     },
-    "hairballi-hair": {
-      "shape": "hairballi",
-      "material": "hairballi-hair"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+    {
+      "name": "hairballi-hair",
+      "shape": 8,
+      "material": 8
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/furnace1/furnace1.json b/tests/furnace1/furnace1.json
index 698403a12..e05209ad7 100644
--- a/tests/furnace1/furnace1.json
+++ b/tests/furnace1/furnace1.json
@@ -2,45 +2,45 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
-      "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.0, 0.0, 1.0]
-      ],
+  "cameras": [
+    {
+      "name": "default",
+      "frame": [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0],
       "aspect": 2.4000000953674316,
       "focus": 1.0
     }
-  },
-  "materials": {
-    "sphere": {
+  ],
+  "environments": [
+    {
+      "name": "env",
+      "emission": [0.5, 0.5, 0.5]
+    }
+  ],
+  "materials": [
+    {
+      "name": "sphere",
       "type": "reflective",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.5
     }
-  },
-  "shapes": {
-    "sphere": "sphere.ply"
-  },
-  "instances": {
-    "sphere": {
+  ],
+  "shapes": [
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "sphere",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.0, -0.07500000298023224, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, -0.07500000298023224,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere"
-    }
-  },
-  "environments": {
-    "env": {
-      "emission": [0.5, 0.5, 0.5]
+      "shape": 0,
+      "material": 0
     }
-  }
+  ]
 }
diff --git a/tests/furnace2/furnace2.json b/tests/furnace2/furnace2.json
index 859a55022..c18632da1 100644
--- a/tests/furnace2/furnace2.json
+++ b/tests/furnace2/furnace2.json
@@ -1,272 +1,331 @@
 {
   "asset": {
-    "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl"
+    "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "lens": 0.1,
       "aperture": 0.0,
       "aspect": 1,
       "lookat": [0, 0.075, 3, 0, 0.075, 0, 0, 1, 0]
     }
-  },
-  "environments": {
-    "furnace": {
+  ],
+  "environments": [
+    {
+      "name": "furnace",
       "emission": [0.5, 0.5, 0.5]
     }
-  },
-  "instances": {
-    "metallic-0": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0.4, 0],
-      "material": "metallic-0"
-    },
-    "metallic-0.25": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0.4, 0],
-      "material": "metallic-0.25"
-    },
-    "metallic-0.5": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.4, 0],
-      "material": "metallic-0.5"
-    },
-    "metallic-0.75": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0.4, 0],
-      "material": "metallic-0.75"
-    },
-    "metallic-1": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0.4, 0],
-      "material": "metallic-1"
-    },
-    "transparent-0": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0.2, 0],
-      "material": "transparent-0"
-    },
-    "transparent-0.25": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0.2, 0],
-      "material": "transparent-0.25"
-    },
-    "transparent-0.5": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.2, 0],
-      "material": "transparent-0.5"
-    },
-    "transparent-0.75": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0.2, 0],
-      "material": "transparent-0.75"
-    },
-    "transparent-1": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0.2, 0],
-      "material": "transparent-1"
-    },
-    "refractive-0": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0, 0],
-      "material": "refractive-0"
-    },
-    "refractive-0.25": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0, 0],
-      "material": "refractive-0.25"
-    },
-    "refractive-0.5": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
-      "material": "refractive-0.5"
-    },
-    "refractive-0.75": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0, 0],
-      "material": "refractive-0.75"
-    },
-    "refractive-1": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0, 0],
-      "material": "refractive-1"
-    },
-    "matte-0": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, -0.2, 0],
-      "material": "matte-0"
-    },
-    "matte-0.25": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, -0.2, 0],
-      "material": "matte-0.25"
-    },
-    "matte-0.5": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -0.2, 0],
-      "material": "matte-0.5"
-    },
-    "matte-0.75": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, -0.2, 0],
-      "material": "matte-0.75"
-    },
-    "matte-1": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, -0.2, 0],
-      "material": "matte-1"
-    },
-    "glossy-0": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, -0.4, 0],
-      "material": "glossy-0"
-    },
-    "glossy-0.25": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, -0.4, 0],
-      "material": "glossy-0.25"
-    },
-    "glossy-0.5": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -0.4, 0],
-      "material": "glossy-0.5"
-    },
-    "glossy-0.75": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, -0.4, 0],
-      "material": "glossy-0.75"
-    },
-    "glossy-1": {
-      "shape": "sphere",
-      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, -0.4, 0],
-      "material": "glossy-1"
-    }
-  },
-  "materials": {
-    "metallic-0": {
+  ],
+  "materials": [
+    {
+      "name": "metallic-0",
       "type": "reflective",
       "color": [1, 1, 1],
       "roughness": 0
     },
-    "metallic-0.25": {
+    {
+      "name": "metallic-0.25",
       "type": "reflective",
       "color": [1, 1, 1],
       "roughness": 0.25
     },
-    "metallic-0.5": {
+    {
+      "name": "metallic-0.5",
       "type": "reflective",
       "color": [1, 1, 1],
       "roughness": 0.5
     },
-    "metallic-0.75": {
+    {
+      "name": "metallic-0.75",
       "type": "reflective",
       "color": [1, 1, 1],
       "roughness": 0.75
     },
-    "metallic-1": {
+    {
+      "name": "metallic-1",
       "type": "reflective",
       "color": [1, 1, 1],
       "roughness": 1
     },
-    "transparent-0": {
+    {
+      "name": "transparent-0",
       "type": "transparent",
       "color": [1, 1, 1],
       "roughness": 0
     },
-    "transparent-0.25": {
+    {
+      "name": "transparent-0.25",
       "type": "transparent",
       "color": [1, 1, 1],
       "roughness": 0.25
     },
-    "transparent-0.5": {
+    {
+      "name": "transparent-0.5",
       "type": "transparent",
       "color": [1, 1, 1],
       "roughness": 0.5
     },
-    "transparent-0.75": {
+    {
+      "name": "transparent-0.75",
       "type": "transparent",
       "color": [1, 1, 1],
       "roughness": 0.75
     },
-    "transparent-1": {
+    {
+      "name": "transparent-1",
       "type": "transparent",
       "color": [1, 1, 1],
       "roughness": 1
     },
-    "refractive-0": {
+    {
+      "name": "refractive-0",
       "type": "refractive",
       "color": [1, 1, 1],
       "roughness": 0
     },
-    "refractive-0.25": {
+    {
+      "name": "refractive-0.25",
       "type": "refractive",
       "color": [1, 1, 1],
       "roughness": 0.25
     },
-    "refractive-0.5": {
+    {
+      "name": "refractive-0.5",
       "type": "refractive",
       "color": [1, 1, 1],
       "roughness": 0.5
     },
-    "refractive-0.75": {
+    {
+      "name": "refractive-0.75",
       "type": "refractive",
       "color": [1, 1, 1],
       "roughness": 0.75
     },
-    "refractive-1": {
+    {
+      "name": "refractive-1",
       "type": "refractive",
       "color": [1, 1, 1],
       "roughness": 1
     },
-    "matte-0": {
+    {
+      "name": "matte-0",
       "type": "matte",
       "color": [1, 1, 1],
       "roughness": 0
     },
-    "matte-0.25": {
+    {
+      "name": "matte-0.25",
       "type": "matte",
       "color": [1, 1, 1],
       "roughness": 0.25
     },
-    "matte-0.5": {
+    {
+      "name": "matte-0.5",
       "type": "matte",
       "color": [1, 1, 1],
       "roughness": 0.5
     },
-    "matte-0.75": {
+    {
+      "name": "matte-0.75",
       "type": "matte",
       "color": [1, 1, 1],
       "roughness": 0.75
     },
-    "matte-1": {
+    {
+      "name": "matte-1",
       "type": "matte",
       "color": [1, 1, 1],
       "roughness": 1
     },
-    "glossy-0": {
+    {
+      "name": "glossy-0",
       "type": "glossy",
       "color": [1, 1, 1],
       "roughness": 0
     },
-    "glossy-0.25": {
+    {
+      "name": "glossy-0.25",
       "type": "glossy",
       "color": [1, 1, 1],
       "roughness": 0.25
     },
-    "glossy-0.5": {
+    {
+      "name": "glossy-0.5",
       "type": "glossy",
       "color": [1, 1, 1],
       "roughness": 0.5
     },
-    "glossy-0.75": {
+    {
+      "name": "glossy-0.75",
       "type": "glossy",
       "color": [1, 1, 1],
       "roughness": 0.75
     },
-    "glossy-1": {
+    {
+      "name": "glossy-1",
       "type": "glossy",
       "color": [1, 1, 1],
       "roughness": 1
     }
-  }
+  ],
+  "shapes": [
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "metallic-0",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0.4, 0],
+      "material": 0
+    },
+    {
+      "name": "metallic-0.25",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0.4, 0],
+      "material": 1
+    },
+    {
+      "name": "metallic-0.5",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.4, 0],
+      "material": 2
+    },
+    {
+      "name": "metallic-0.75",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0.4, 0],
+      "material": 3
+    },
+    {
+      "name": "metallic-1",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0.4, 0],
+      "material": 4
+    },
+    {
+      "name": "transparent-0",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0.2, 0],
+      "material": 5
+    },
+    {
+      "name": "transparent-0.25",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0.2, 0],
+      "material": 6
+    },
+    {
+      "name": "transparent-0.5",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.2, 0],
+      "material": 7
+    },
+    {
+      "name": "transparent-0.75",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0.2, 0],
+      "material": 8
+    },
+    {
+      "name": "transparent-1",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0.2, 0],
+      "material": 9
+    },
+    {
+      "name": "refractive-0",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, 0, 0],
+      "material": 10
+    },
+    {
+      "name": "refractive-0.25",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, 0, 0],
+      "material": 11
+    },
+    {
+      "name": "refractive-0.5",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
+      "material": 12
+    },
+    {
+      "name": "refractive-0.75",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, 0, 0],
+      "material": 13
+    },
+    {
+      "name": "refractive-1",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, 0, 0],
+      "material": 14
+    },
+    {
+      "name": "matte-0",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, -0.2, 0],
+      "material": 15
+    },
+    {
+      "name": "matte-0.25",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, -0.2, 0],
+      "material": 16
+    },
+    {
+      "name": "matte-0.5",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -0.2, 0],
+      "material": 17
+    },
+    {
+      "name": "matte-0.75",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, -0.2, 0],
+      "material": 18
+    },
+    {
+      "name": "matte-1",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, -0.2, 0],
+      "material": 19
+    },
+    {
+      "name": "glossy-0",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.4, -0.4, 0],
+      "material": 20
+    },
+    {
+      "name": "glossy-0.25",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, -0.2, -0.4, 0],
+      "material": 21
+    },
+    {
+      "name": "glossy-0.5",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -0.4, 0],
+      "material": 22
+    },
+    {
+      "name": "glossy-0.75",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.2, -0.4, 0],
+      "material": 23
+    },
+    {
+      "name": "glossy-1",
+      "shape": 0,
+      "frame": [1, 0, 0, 0, 1, 0, 0, 0, 1, 0.4, -0.4, 0],
+      "material": 24
+    }
+  ]
 }
diff --git a/tests/instances1/instances1.json b/tests/instances1/instances1.json
index cc6ab0fcc..80749238b 100644
--- a/tests/instances1/instances1.json
+++ b/tests/instances1/instances1.json
@@ -2,147 +2,182 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, -0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, 0.936329185962677 ],
-        [ 0.0, 0.574999988079071, 1.399999976158142 ]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, 0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, -0.936329185962677 ],
-        [ 0.0, 0.574999988079071, -1.399999976158142 ]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
     },
-    "sphere-uvgrid": {
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
+    },
+    {
+      "name": "sphere-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.20000000298023224,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "arealight1": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight1",
+      "emission": [20.0, 20.0, 20.0]
     },
-    "arealight2": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight2",
+      "emission": [20.0, 20.0, 20.0]
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "sphere": "sphere.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
     },
-    "sphere": {
-      "shape": "sphere",
-      "material": "sphere-uvgrid"
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
     },
-    "arealight1": {
+    {
+      "name": "sphere",
+      "shape": 1,
+      "material": 1
+    },
+    {
+      "name": "arealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ -0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ -0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 2,
+      "material": 2
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ 0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ 0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 3,
+      "material": 3
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/materials1/materials1.json b/tests/materials1/materials1.json
index 57ab4874c..7249babbd 100644
--- a/tests/materials1/materials1.json
+++ b/tests/materials1/materials1.json
@@ -2,83 +2,81 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.8853979110717773, -0.46483391523361206],
-        [0.0, 0.46483391523361206, 0.8853979110717773],
-        [0.0, 1.75, 3.0]
+        1.0, 0.0, 0.0, 0.0, 0.8853979110717773, -0.46483391523361206, 0.0,
+        0.46483391523361206, 0.8853979110717773, 0.0, 1.75, 3.0
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.3883070945739746
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.9026037454605103, 0.4304725229740143],
-        [0.0, 0.4304724931716919, -0.9026036858558655],
-        [0.0, 1.5, -3.25]
+        -1.0, 0.0, 0.0, 0.0, 0.9026037454605103, 0.4304725229740143, 0.0,
+        0.4304724931716919, -0.9026036858558655, 0.0, 1.5, -3.25
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.600694417953491
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785,
       "aperture": 0.05000000074505806
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.9756097197532654, -0.0, 0.2195121943950653],
-        [0.08407647162675858, 0.9237421154975891, -0.3736732006072998],
-        [-0.20277264714241028, 0.3830150067806244, 0.9012117385864258],
-        [-0.5, 1.0, 2.0]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
       "aspect": 2.4000000953674316,
       "focus": 2.2192342281341553
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.9756097197532654, -0.0, 0.2195121943950653],
-        [0.08407647162675858, 0.9237421154975891, -0.3736732006072998],
-        [-0.20277264714241028, 0.3830150067806244, 0.9012117385864258],
-        [-0.5, 1.0, 2.0]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
@@ -86,200 +84,230 @@
       "focus": 2.2192342281341553,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
       "emission": [10.0, 10.0, 10.0]
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "emission": [10.0, 10.0, 10.0]
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "sphere-matte": {
+    {
+      "name": "sphere-matte",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "sphere-metal-sharp": {
+    {
+      "name": "sphere-metal-sharp",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071]
     },
-    "sphere-metal-rough": {
+    {
+      "name": "sphere-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "bunny-plastic-sharp": {
+    {
+      "name": "bunny-plastic-sharp",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "bunny-plastic-rough": {
+    {
+      "name": "bunny-plastic-rough",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "bunny-matte": {
+    {
+      "name": "bunny-matte",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071]
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "largearealight1": "largearealight1.ply",
-    "largearealight2": "largearealight2.ply",
-    "sphere": "sphere.ply",
-    "bunny": "bunny.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
+      "uri": "shapes/largearealight1.ply"
+    },
+    {
+      "name": "largearealight2",
+      "uri": "shapes/largearealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "largearealight1",
       "frame": [
-        [0.8944271802902222, -0.0, 0.4472135901451111],
-        [0.2873478829860687, 0.766261100769043, -0.5746957659721375],
-        [-0.3426823318004608, 0.6425293684005737, 0.6853646636009216],
-        [-0.800000011920929, 1.600000023841858, 1.600000023841858]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, -0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, -0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight1",
-      "material": "largearealight1"
+      "shape": 1,
+      "material": 1
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "frame": [
-        [0.8944271802902222, 0.0, -0.4472135901451111],
-        [-0.2873478829860687, 0.766261100769043, -0.5746957659721375],
-        [0.3426823318004608, 0.6425293684005737, 0.6853646636009216],
-        [0.800000011920929, 1.600000023841858, 1.600000023841858]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, 0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, 0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight2",
-      "material": "largearealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-plastic-sharp": {
+    {
+      "name": "sphere-plastic-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-sharp"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-plastic-rough": {
+    {
+      "name": "sphere-plastic-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough"
+      "shape": 3,
+      "material": 4
     },
-    "sphere-matte": {
-      "shape": "sphere",
-      "material": "sphere-matte"
+    {
+      "name": "sphere-matte",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-metal-sharp": {
+    {
+      "name": "sphere-metal-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-metal-sharp"
+      "shape": 3,
+      "material": 6
     },
-    "sphere-metal-rough": {
+    {
+      "name": "sphere-metal-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-metal-rough"
+      "shape": 3,
+      "material": 7
     },
-    "bunny-plastic-sharp": {
+    {
+      "name": "bunny-plastic-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-plastic-sharp"
+      "shape": 4,
+      "material": 8
     },
-    "bunny-plastic-rough": {
+    {
+      "name": "bunny-plastic-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-plastic-rough"
+      "shape": 4,
+      "material": 9
     },
-    "bunny-matte": {
+    {
+      "name": "bunny-matte",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.0, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-matte"
+      "shape": 4,
+      "material": 10
     },
-    "bunny-metal-sharp": {
+    {
+      "name": "bunny-metal-sharp",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-sharp"
+      "shape": 4,
+      "material": 11
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [0.5, 0.5, 0.5],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 12
     }
-  }
+  ]
 }
diff --git a/tests/materials2/materials2.json b/tests/materials2/materials2.json
index 07130c29d..d850ab301 100644
--- a/tests/materials2/materials2.json
+++ b/tests/materials2/materials2.json
@@ -2,83 +2,81 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.8853979110717773, -0.46483391523361206 ],
-        [ 0.0, 0.46483391523361206, 0.8853979110717773 ],
-        [ 0.0, 1.75, 3.0 ]
+        1.0, 0.0, 0.0, 0.0, 0.8853979110717773, -0.46483391523361206, 0.0,
+        0.46483391523361206, 0.8853979110717773, 0.0, 1.75, 3.0
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.3883070945739746
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.9026037454605103, 0.4304725229740143 ],
-        [ 0.0, 0.4304724931716919, -0.9026036858558655 ],
-        [ 0.0, 1.5, -3.25 ]
+        -1.0, 0.0, 0.0, 0.0, 0.9026037454605103, 0.4304725229740143, 0.0,
+        0.4304724931716919, -0.9026036858558655, 0.0, 1.5, -3.25
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.600694417953491
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785,
       "aperture": 0.05000000074505806
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
       "aspect": 2.4000000953674316,
       "focus": 2.2192342281341553
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
@@ -86,200 +84,230 @@
       "focus": 2.2192342281341553,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
     },
-    "largearealight1": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "largearealight2": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "largearealight1",
+      "emission": [10.0, 10.0, 10.0]
     },
-    "sphere-glass-sharp": {
+    {
+      "name": "largearealight2",
+      "emission": [10.0, 10.0, 10.0]
+    },
+    {
+      "name": "sphere-glass-sharp",
       "type": "refractive",
-      "color": [ 1.0, 1.0, 1.0 ]
+      "color": [1.0, 1.0, 1.0]
     },
-    "sphere-glass-rough": {
+    {
+      "name": "sphere-glass-rough",
       "type": "refractive",
-      "color": [ 1.0, 0.699999988079071, 0.699999988079071 ],
+      "color": [1.0, 0.699999988079071, 0.699999988079071],
       "roughness": 0.10000000149011612
     },
-    "sphere-transparent": {
-      "color": [ 0.699999988079071, 0.5, 0.5 ],
+    {
+      "name": "sphere-transparent",
+      "color": [0.699999988079071, 0.5, 0.5],
       "roughness": 1.0,
       "opacity": 0.20000000298023224
     },
-    "sphere-thinglass-sharp": {
+    {
+      "name": "sphere-thinglass-sharp",
       "type": "transparent",
-      "color": [ 1.0, 1.0, 1.0 ]
+      "color": [1.0, 1.0, 1.0]
     },
-    "sphere-thinglass-rough": {
+    {
+      "name": "sphere-thinglass-rough",
       "type": "transparent",
-      "color": [ 1.0, 0.699999988079071, 0.699999988079071 ],
+      "color": [1.0, 0.699999988079071, 0.699999988079071],
       "roughness": 0.05000000074505806
     },
-    "bunny-glass-sharp": {
+    {
+      "name": "bunny-glass-sharp",
       "type": "refractive",
-      "color": [ 1.0, 1.0, 1.0 ]
+      "color": [1.0, 1.0, 1.0]
     },
-    "bunny-glass-rough": {
+    {
+      "name": "bunny-glass-rough",
       "type": "refractive",
-      "color": [ 1.0, 0.699999988079071, 0.699999988079071 ],
+      "color": [1.0, 0.699999988079071, 0.699999988079071],
       "roughness": 0.10000000149011612
     },
-    "bunny-transparent": {
-      "color": [ 0.699999988079071, 0.5, 0.5 ],
+    {
+      "name": "bunny-transparent",
+      "color": [0.699999988079071, 0.5, 0.5],
       "roughness": 1.0,
       "opacity": 0.20000000298023224
     },
-    "bunny-thinglass-sharp": {
+    {
+      "name": "bunny-thinglass-sharp",
       "type": "transparent",
-      "color": [ 1.0, 1.0, 1.0 ]
+      "color": [1.0, 1.0, 1.0]
     },
-    "bunny-thinglass-rough": {
+    {
+      "name": "bunny-thinglass-rough",
       "type": "transparent",
-      "color": [ 1.0, 0.699999988079071, 0.699999988079071 ],
+      "color": [1.0, 0.699999988079071, 0.699999988079071],
       "roughness": 0.05000000074505806
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "largearealight1": "largearealight1.ply",
-    "largearealight2": "largearealight2.ply",
-    "sphere": "sphere.ply",
-    "bunny": "bunny.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
+      "uri": "shapes/largearealight1.ply"
+    },
+    {
+      "name": "largearealight2",
+      "uri": "shapes/largearealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "largearealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ -0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ -0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, -0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, -0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight1",
-      "material": "largearealight1"
+      "shape": 1,
+      "material": 1
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ 0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ 0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, 0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, 0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight2",
-      "material": "largearealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-glass-sharp": {
+    {
+      "name": "sphere-glass-sharp",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-glass-sharp"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-glass-rough": {
+    {
+      "name": "sphere-glass-rough",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-glass-rough"
+      "shape": 3,
+      "material": 4
     },
-    "sphere-transparent": {
-      "shape": "sphere",
-      "material": "sphere-transparent"
+    {
+      "name": "sphere-transparent",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-thinglass-sharp": {
+    {
+      "name": "sphere-thinglass-sharp",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-thinglass-sharp"
+      "shape": 3,
+      "material": 6
     },
-    "sphere-thinglass-rough": {
+    {
+      "name": "sphere-thinglass-rough",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-thinglass-rough"
+      "shape": 3,
+      "material": 7
     },
-    "bunny-glass-sharp": {
+    {
+      "name": "bunny-glass-sharp",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-glass-sharp"
+      "shape": 4,
+      "material": 8
     },
-    "bunny-glass-rough": {
+    {
+      "name": "bunny-glass-rough",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-glass-rough"
+      "shape": 4,
+      "material": 9
     },
-    "bunny-transparent": {
+    {
+      "name": "bunny-transparent",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.0, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-transparent"
+      "shape": 4,
+      "material": 10
     },
-    "bunny-thinglass-sharp": {
+    {
+      "name": "bunny-thinglass-sharp",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-thinglass-sharp"
+      "shape": 4,
+      "material": 11
     },
-    "bunny-thinglass-rough": {
+    {
+      "name": "bunny-thinglass-rough",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-thinglass-rough"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 12
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/materials3/materials3.json b/tests/materials3/materials3.json
index cd9516685..9ceb12cfc 100644
--- a/tests/materials3/materials3.json
+++ b/tests/materials3/materials3.json
@@ -2,83 +2,81 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.8853979110717773, -0.46483391523361206],
-        [0.0, 0.46483391523361206, 0.8853979110717773],
-        [0.0, 1.75, 3.0]
+        1.0, 0.0, 0.0, 0.0, 0.8853979110717773, -0.46483391523361206, 0.0,
+        0.46483391523361206, 0.8853979110717773, 0.0, 1.75, 3.0
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.3883070945739746
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.9026037454605103, 0.4304725229740143],
-        [0.0, 0.4304724931716919, -0.9026036858558655],
-        [0.0, 1.5, -3.25]
+        -1.0, 0.0, 0.0, 0.0, 0.9026037454605103, 0.4304725229740143, 0.0,
+        0.4304724931716919, -0.9026036858558655, 0.0, 1.5, -3.25
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.600694417953491
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.9805806875228882, -0.0, 0.1961161345243454],
-        [0.08506310731172562, 0.9010388255119324, -0.4253155291080475],
-        [-0.17670825123786926, 0.43373844027519226, 0.8835412859916687],
-        [-0.6000000238418579, 1.5, 2.75]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785,
       "aperture": 0.05000000074505806
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.9756097197532654, -0.0, 0.2195121943950653],
-        [0.08407647162675858, 0.9237421154975891, -0.3736732006072998],
-        [-0.20277264714241028, 0.3830150067806244, 0.9012117385864258],
-        [-0.5, 1.0, 2.0]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
       "aspect": 2.4000000953674316,
       "focus": 2.2192342281341553
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.9756097197532654, -0.0, 0.2195121943950653],
-        [0.08407647162675858, 0.9237421154975891, -0.3736732006072998],
-        [-0.20277264714241028, 0.3830150067806244, 0.9012117385864258],
-        [-0.5, 1.0, 2.0]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
@@ -86,207 +84,240 @@
       "focus": 2.2192342281341553,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "bumps-normal": "bumps-normal.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "bumps-normal",
+      "uri": "textures/bumps-normal.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
       "emission": [10.0, 10.0, 10.0]
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "emission": [10.0, 10.0, 10.0]
     },
-    "sphere-plastic-sharp-bumped": {
+    {
+      "name": "sphere-plastic-sharp-bumped",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582,
-      "normal_tex": "bumps-normal"
+      "normal_tex": 2
     },
-    "sphere-plastic-rough-coated": {
+    {
+      "name": "sphere-plastic-rough-coated",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "sphere-metal-sharp-bumped": {
+    {
+      "name": "sphere-metal-sharp-bumped",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "normal_tex": "bumps-normal"
+      "normal_tex": 2
     },
-    "sphere-metal-rough-coated": {
+    {
+      "name": "sphere-metal-rough-coated",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "sphere-metal-rough": {
+    {
+      "name": "sphere-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "bunny-plastic-sharp-bumped": {
+    {
+      "name": "bunny-plastic-sharp-bumped",
       "type": "glossy",
       "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582,
-      "normal_tex": "bumps-normal"
+      "normal_tex": 2
     },
-    "bunny-plastic-rough-coated": {
+    {
+      "name": "bunny-plastic-rough-coated",
       "type": "glossy",
       "color": [0.5, 0.699999988079071, 0.5],
       "roughness": 0.20000000298023224
     },
-    "bunny-metal-sharp-bumped": {
+    {
+      "name": "bunny-metal-sharp-bumped",
       "type": "reflective",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "normal_tex": "bumps-normal"
+      "normal_tex": 2
     },
-    "bunny-metal-rough-coated": {
+    {
+      "name": "bunny-metal-rough-coated",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "type": "reflective",
       "color": [0.6600000262260437, 0.44999998807907104, 0.3400000035762787],
       "roughness": 0.20000000298023224
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "largearealight1": "largearealight1.ply",
-    "largearealight2": "largearealight2.ply",
-    "sphere": "sphere.ply",
-    "bunny": "bunny.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
+      "uri": "shapes/largearealight1.ply"
+    },
+    {
+      "name": "largearealight2",
+      "uri": "shapes/largearealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "largearealight1",
       "frame": [
-        [0.8944271802902222, -0.0, 0.4472135901451111],
-        [0.2873478829860687, 0.766261100769043, -0.5746957659721375],
-        [-0.3426823318004608, 0.6425293684005737, 0.6853646636009216],
-        [-0.800000011920929, 1.600000023841858, 1.600000023841858]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, -0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, -0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight1",
-      "material": "largearealight1"
+      "shape": 1,
+      "material": 1
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "frame": [
-        [0.8944271802902222, 0.0, -0.4472135901451111],
-        [-0.2873478829860687, 0.766261100769043, -0.5746957659721375],
-        [0.3426823318004608, 0.6425293684005737, 0.6853646636009216],
-        [0.800000011920929, 1.600000023841858, 1.600000023841858]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, 0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, 0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight2",
-      "material": "largearealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-plastic-sharp-bumped": {
+    {
+      "name": "sphere-plastic-sharp-bumped",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-sharp-bumped"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-plastic-rough-coated": {
+    {
+      "name": "sphere-plastic-rough-coated",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-plastic-rough-coated"
+      "shape": 3,
+      "material": 4
     },
-    "sphere-metal-sharp-bumped": {
-      "shape": "sphere",
-      "material": "sphere-metal-sharp-bumped"
+    {
+      "name": "sphere-metal-sharp-bumped",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-metal-rough-coated": {
+    {
+      "name": "sphere-metal-rough-coated",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-metal-rough-coated"
+      "shape": 3,
+      "material": 6
     },
-    "sphere-metal-rough": {
+    {
+      "name": "sphere-metal-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-metal-rough"
+      "shape": 3,
+      "material": 7
     },
-    "bunny-plastic-sharp-bumped": {
+    {
+      "name": "bunny-plastic-sharp-bumped",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-plastic-sharp-bumped"
+      "shape": 4,
+      "material": 8
     },
-    "bunny-plastic-rough-coated": {
+    {
+      "name": "bunny-plastic-rough-coated",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-plastic-rough-coated"
+      "shape": 4,
+      "material": 9
     },
-    "bunny-metal-sharp-bumped": {
+    {
+      "name": "bunny-metal-sharp-bumped",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.0, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-sharp-bumped"
+      "shape": 4,
+      "material": 10
     },
-    "bunny-metal-rough-coated": {
+    {
+      "name": "bunny-metal-rough-coated",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-rough-coated"
+      "shape": 4,
+      "material": 11
     },
-    "bunny-metal-rough": {
+    {
+      "name": "bunny-metal-rough",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, -0.4000000059604645]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-metal-rough"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [0.5, 0.5, 0.5],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 12
     }
-  }
+  ]
 }
diff --git a/tests/materials4/materials4.json b/tests/materials4/materials4.json
index 12d6b51a9..a54c52f6f 100644
--- a/tests/materials4/materials4.json
+++ b/tests/materials4/materials4.json
@@ -2,83 +2,81 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.8853979110717773, -0.46483391523361206 ],
-        [ 0.0, 0.46483391523361206, 0.8853979110717773 ],
-        [ 0.0, 1.75, 3.0 ]
+        1.0, 0.0, 0.0, 0.0, 0.8853979110717773, -0.46483391523361206, 0.0,
+        0.46483391523361206, 0.8853979110717773, 0.0, 1.75, 3.0
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.3883070945739746
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.9026037454605103, 0.4304725229740143 ],
-        [ 0.0, 0.4304724931716919, -0.9026036858558655 ],
-        [ 0.0, 1.5, -3.25 ]
+        -1.0, 0.0, 0.0, 0.0, 0.9026037454605103, 0.4304725229740143, 0.0,
+        0.4304724931716919, -0.9026036858558655, 0.0, 1.5, -3.25
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.600694417953491
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785,
       "aperture": 0.05000000074505806
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
       "aspect": 2.4000000953674316,
       "focus": 2.2192342281341553
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
@@ -86,205 +84,247 @@
       "focus": 2.2192342281341553,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
     },
-    "largearealight1": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "largearealight2": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "largearealight1",
+      "emission": [10.0, 10.0, 10.0]
     },
-    "sphere-volume-cloud": {
+    {
+      "name": "largearealight2",
+      "emission": [10.0, 10.0, 10.0]
+    },
+    {
+      "name": "sphere-volume-cloud",
       "type": "volume",
-      "color": [ 0.6499999761581421, 0.6499999761581421, 0.6499999761581421 ],
-      "scattering": [ 0.8999999761581421, 0.8999999761581421, 0.8999999761581421 ]
+      "color": [0.6499999761581421, 0.6499999761581421, 0.6499999761581421],
+      "scattering": [0.8999999761581421, 0.8999999761581421, 0.8999999761581421]
     },
-    "sphere-volume-glass": {
+    {
+      "name": "sphere-volume-glass",
       "type": "refractive",
-      "color": [ 1.0, 0.5, 0.5 ],
+      "color": [1.0, 0.5, 0.5],
       "trdepth": 0.019999999552965164
     },
-    "sphere-volume-jade": {
+    {
+      "name": "sphere-volume-jade",
       "type": "refractive",
-      "color": [ 0.5, 0.5, 0.5 ],
-      "scattering": [ 0.30000001192092896, 0.6000000238418579, 0.30000001192092896 ]
+      "color": [0.5, 0.5, 0.5],
+      "scattering": [
+        0.30000001192092896, 0.6000000238418579, 0.30000001192092896
+      ]
     },
-    "sphere-volume-jade2": {
+    {
+      "name": "sphere-volume-jade2",
       "type": "refractive",
-      "color": [ 0.5, 0.5, 0.5 ],
-      "scattering": [ 0.30000001192092896, 0.6000000238418579, 0.30000001192092896 ]
+      "color": [0.5, 0.5, 0.5],
+      "scattering": [
+        0.30000001192092896, 0.6000000238418579, 0.30000001192092896
+      ]
     },
-    "sphere-volume-smoke": {
+    {
+      "name": "sphere-volume-smoke",
       "type": "volume",
-      "color": [ 0.5, 0.5, 0.5 ],
-      "scattering": [ 0.20000000298023224, 0.20000000298023224, 0.20000000298023224 ]
+      "color": [0.5, 0.5, 0.5],
+      "scattering": [
+        0.20000000298023224, 0.20000000298023224, 0.20000000298023224
+      ]
     },
-    "bunny-volume-cloud": {
+    {
+      "name": "bunny-volume-cloud",
       "type": "volume",
-      "color": [ 0.6499999761581421, 0.6499999761581421, 0.6499999761581421 ],
-      "scattering": [ 0.8999999761581421, 0.8999999761581421, 0.8999999761581421 ]
+      "color": [0.6499999761581421, 0.6499999761581421, 0.6499999761581421],
+      "scattering": [0.8999999761581421, 0.8999999761581421, 0.8999999761581421]
     },
-    "bunny-volume-glass": {
+    {
+      "name": "bunny-volume-glass",
       "type": "refractive",
-      "color": [ 1.0, 0.5, 0.5 ],
+      "color": [1.0, 0.5, 0.5],
       "trdepth": 0.019999999552965164
     },
-    "bunny-volume-jade": {
+    {
+      "name": "bunny-volume-jade",
       "type": "refractive",
-      "color": [ 0.5, 0.5, 0.5 ],
-      "scattering": [ 0.30000001192092896, 0.6000000238418579, 0.30000001192092896 ]
+      "color": [0.5, 0.5, 0.5],
+      "scattering": [
+        0.30000001192092896, 0.6000000238418579, 0.30000001192092896
+      ]
     },
-    "bunny-volume-jade2": {
+    {
+      "name": "bunny-volume-jade2",
       "type": "refractive",
-      "color": [ 0.5, 0.5, 0.5 ],
+      "color": [0.5, 0.5, 0.5],
       "roughness": 0.10000000149011612,
-      "scattering": [ 0.30000001192092896, 0.6000000238418579, 0.30000001192092896 ]
+      "scattering": [
+        0.30000001192092896, 0.6000000238418579, 0.30000001192092896
+      ]
     },
-    "bunny-volume-smoke": {
+    {
+      "name": "bunny-volume-smoke",
       "type": "volume",
-      "color": [ 0.5, 0.5, 0.5 ],
-      "scattering": [ 0.20000000298023224, 0.20000000298023224, 0.20000000298023224 ]
+      "color": [0.5, 0.5, 0.5],
+      "scattering": [
+        0.20000000298023224, 0.20000000298023224, 0.20000000298023224
+      ]
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "largearealight1": "largearealight1.ply",
-    "largearealight2": "largearealight2.ply",
-    "sphere": "sphere.ply",
-    "bunny": "bunny.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
     },
-    "largearealight1": {
+    {
+      "name": "largearealight1",
+      "uri": "shapes/largearealight1.ply"
+    },
+    {
+      "name": "largearealight2",
+      "uri": "shapes/largearealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "largearealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ -0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ -0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, -0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, -0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight1",
-      "material": "largearealight1"
+      "shape": 1,
+      "material": 1
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ 0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ 0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, 0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, 0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight2",
-      "material": "largearealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-volume-cloud": {
+    {
+      "name": "sphere-volume-cloud",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-volume-cloud"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-volume-glass": {
+    {
+      "name": "sphere-volume-glass",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-volume-glass"
+      "shape": 3,
+      "material": 4
     },
-    "sphere-volume-jade": {
-      "shape": "sphere",
-      "material": "sphere-volume-jade"
+    {
+      "name": "sphere-volume-jade",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-volume-jade2": {
+    {
+      "name": "sphere-volume-jade2",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-volume-jade2"
+      "shape": 3,
+      "material": 6
     },
-    "sphere-volume-smoke": {
+    {
+      "name": "sphere-volume-smoke",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-volume-smoke"
+      "shape": 3,
+      "material": 7
     },
-    "bunny-volume-cloud": {
+    {
+      "name": "bunny-volume-cloud",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-volume-cloud"
+      "shape": 4,
+      "material": 8
     },
-    "bunny-volume-glass": {
+    {
+      "name": "bunny-volume-glass",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-volume-glass"
+      "shape": 4,
+      "material": 9
     },
-    "bunny-volume-jade": {
+    {
+      "name": "bunny-volume-jade",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.0, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-volume-jade"
+      "shape": 4,
+      "material": 10
     },
-    "bunny-volume-jade2": {
+    {
+      "name": "bunny-volume-jade2",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-volume-jade2"
+      "shape": 4,
+      "material": 11
     },
-    "bunny-volume-smoke": {
+    {
+      "name": "bunny-volume-smoke",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "bunny-volume-smoke"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 12
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/materials5/materials5.json b/tests/materials5/materials5.json
index aaad4c236..55b70ac78 100644
--- a/tests/materials5/materials5.json
+++ b/tests/materials5/materials5.json
@@ -2,83 +2,81 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.8853979110717773, -0.46483391523361206 ],
-        [ 0.0, 0.46483391523361206, 0.8853979110717773 ],
-        [ 0.0, 1.75, 3.0 ]
+        1.0, 0.0, 0.0, 0.0, 0.8853979110717773, -0.46483391523361206, 0.0,
+        0.46483391523361206, 0.8853979110717773, 0.0, 1.75, 3.0
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.3883070945739746
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.9026037454605103, 0.4304725229740143 ],
-        [ 0.0, 0.4304724931716919, -0.9026036858558655 ],
-        [ 0.0, 1.5, -3.25 ]
+        -1.0, 0.0, 0.0, 0.0, 0.9026037454605103, 0.4304725229740143, 0.0,
+        0.4304724931716919, -0.9026036858558655, 0.0, 1.5, -3.25
       ],
       "lens": 0.10000000149011612,
       "aspect": 3.0,
       "focus": 3.600694417953491
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.9805806875228882, -0.0, 0.1961161345243454 ],
-        [ 0.08506310731172562, 0.9010388255119324, -0.4253155291080475 ],
-        [ -0.17670825123786926, 0.43373844027519226, 0.8835412859916687 ],
-        [ -0.6000000238418579, 1.5, 2.75 ]
+        0.9805806875228882, -0.0, 0.1961161345243454, 0.08506310731172562,
+        0.9010388255119324, -0.4253155291080475, -0.17670825123786926,
+        0.43373844027519226, 0.8835412859916687, -0.6000000238418579, 1.5, 2.75
       ],
       "lens": 0.10000000149011612,
       "aspect": 2.4000000953674316,
       "focus": 3.1124749183654785,
       "aperture": 0.05000000074505806
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
       "aspect": 2.4000000953674316,
       "focus": 2.2192342281341553
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.9756097197532654, -0.0, 0.2195121943950653 ],
-        [ 0.08407647162675858, 0.9237421154975891, -0.3736732006072998 ],
-        [ -0.20277264714241028, 0.3830150067806244, 0.9012117385864258 ],
-        [ -0.5, 1.0, 2.0 ]
+        0.9756097197532654, -0.0, 0.2195121943950653, 0.08407647162675858,
+        0.9237421154975891, -0.3736732006072998, -0.20277264714241028,
+        0.3830150067806244, 0.9012117385864258, -0.5, 1.0, 2.0
       ],
       "orthographic": true,
       "lens": 0.029999999329447746,
@@ -86,193 +84,228 @@
       "focus": 2.2192342281341553,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "largearealight1": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "largearealight1",
+      "emission": [10.0, 10.0, 10.0]
     },
-    "largearealight2": {
-      "emission": [ 10.0, 10.0, 10.0 ]
+    {
+      "name": "largearealight2",
+      "emission": [10.0, 10.0, 10.0]
     },
-    "skin1a": {
+    {
+      "name": "skin1a",
       "type": "refractive",
-      "color": [ 0.7599999904632568, 0.47999998927116394, 0.23000000417232513 ],
+      "color": [0.7599999904632568, 0.47999998927116394, 0.23000000417232513],
       "roughness": 0.25,
       "trdepth": 0.0010000000474974513,
-      "scattering": [ 0.4359999895095825, 0.22699999809265137, 0.13099999725818634 ],
+      "scattering": [
+        0.4359999895095825, 0.22699999809265137, 0.13099999725818634
+      ],
       "scanisotropy": -0.800000011920929
     },
-    "skin2a": {
+    {
+      "name": "skin2a",
       "type": "refractive",
-      "color": [ 0.8199999928474426, 0.550000011920929, 0.4000000059604645 ],
+      "color": [0.8199999928474426, 0.550000011920929, 0.4000000059604645],
       "roughness": 0.25,
       "trdepth": 0.0010000000474974513,
-      "scattering": [ 0.6230000257492065, 0.43299999833106995, 0.34299999475479126 ],
+      "scattering": [
+        0.6230000257492065, 0.43299999833106995, 0.34299999475479126
+      ],
       "scanisotropy": -0.800000011920929
     },
-    "skins": {
+    {
+      "name": "skins",
       "type": "refractive",
-      "color": [ 0.7599999904632568, 0.47999998927116394, 0.23000000417232513 ],
+      "color": [0.7599999904632568, 0.47999998927116394, 0.23000000417232513],
       "trdepth": 0.0010000000474974513,
-      "scattering": [ 0.4359999895095825, 0.22699999809265137, 0.13099999725818634 ],
+      "scattering": [
+        0.4359999895095825, 0.22699999809265137, 0.13099999725818634
+      ],
       "scanisotropy": -0.800000011920929
     },
-    "skin1b": {
+    {
+      "name": "skin1b",
       "type": "refractive",
-      "color": [ 0.7599999904632568, 0.47999998927116394, 0.23000000417232513 ],
+      "color": [0.7599999904632568, 0.47999998927116394, 0.23000000417232513],
       "roughness": 0.25,
       "trdepth": 0.0010000000474974513,
-      "scattering": [ 0.4359999895095825, 0.22699999809265137, 0.13099999725818634 ],
+      "scattering": [
+        0.4359999895095825, 0.22699999809265137, 0.13099999725818634
+      ],
       "scanisotropy": -0.800000011920929
     },
-    "skin2b": {
+    {
+      "name": "skin2b",
       "type": "refractive",
-      "color": [ 0.8199999928474426, 0.550000011920929, 0.4000000059604645 ],
+      "color": [0.8199999928474426, 0.550000011920929, 0.4000000059604645],
       "roughness": 0.25,
       "trdepth": 0.0010000000474974513,
-      "scattering": [ 0.6230000257492065, 0.43299999833106995, 0.34299999475479126 ],
+      "scattering": [
+        0.6230000257492065, 0.43299999833106995, 0.34299999475479126
+      ],
       "scanisotropy": -0.800000011920929
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "largearealight1": "largearealight1.ply",
-    "largearealight2": "largearealight2.ply",
-    "sphere": "sphere.ply",
-    "bunny": "bunny.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "largearealight1",
+      "uri": "shapes/largearealight1.ply"
+    },
+    {
+      "name": "largearealight2",
+      "uri": "shapes/largearealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
     },
-    "largearealight1": {
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "largearealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ -0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ -0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, -0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, -0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight1",
-      "material": "largearealight1"
+      "shape": 1,
+      "material": 1
     },
-    "largearealight2": {
+    {
+      "name": "largearealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.2873478829860687, 0.766261100769043, -0.5746957659721375 ],
-        [ 0.3426823318004608, 0.6425293684005737, 0.6853646636009216 ],
-        [ 0.800000011920929, 1.600000023841858, 1.600000023841858 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.2873478829860687,
+        0.766261100769043, -0.5746957659721375, 0.3426823318004608,
+        0.6425293684005737, 0.6853646636009216, 0.800000011920929,
+        1.600000023841858, 1.600000023841858
       ],
-      "shape": "largearealight2",
-      "material": "largearealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-skin1a": {
+    {
+      "name": "sphere-skin1a",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "skin1a"
+      "shape": 3,
+      "material": 3
     },
-    "sphere-skin2a": {
+    {
+      "name": "sphere-skin2a",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "skin2a"
+      "shape": 3,
+      "material": 4
     },
-    "sphere-skins": {
-      "shape": "sphere",
-      "material": "skins"
+    {
+      "name": "sphere-skins",
+      "shape": 3,
+      "material": 5
     },
-    "sphere-skin1b": {
+    {
+      "name": "sphere-skin1b",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "skin1b"
+      "shape": 3,
+      "material": 6
     },
-    "sphere-skin2b": {
+    {
+      "name": "sphere-skin2b",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "skin2b"
+      "shape": 3,
+      "material": 7
     },
-    "bunny-skin1a": {
+    {
+      "name": "bunny-skin1a",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "skin1a"
+      "shape": 4,
+      "material": 3
     },
-    "bunny-skin2a": {
+    {
+      "name": "bunny-skin2a",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "skin2a"
+      "shape": 4,
+      "material": 4
     },
-    "bunny-skins": {
+    {
+      "name": "bunny-skins",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.0, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "skins"
+      "shape": 4,
+      "material": 5
     },
-    "bunny-skin1b": {
+    {
+      "name": "bunny-skin1b",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "skin1b"
+      "shape": 4,
+      "material": 6
     },
-    "bunny-skin2b": {
+    {
+      "name": "bunny-skin2b",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, -0.4000000059604645 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        -0.4000000059604645
       ],
-      "shape": "bunny",
-      "material": "skin2b"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 4,
+      "material": 7
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/shapes1/shapes1.json b/tests/shapes1/shapes1.json
index 2db08fc55..da482929a 100644
--- a/tests/shapes1/shapes1.json
+++ b/tests/shapes1/shapes1.json
@@ -2,215 +2,262 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, -0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, 0.936329185962677 ],
-        [ 0.0, 0.574999988079071, 1.399999976158142 ]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, 0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, -0.936329185962677 ],
-        [ 0.0, 0.574999988079071, -1.399999976158142 ]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
     },
-    "arealight1": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "arealight2": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight1",
+      "emission": [20.0, 20.0, 20.0]
     },
-    "sphere-uvgrid": {
+    {
+      "name": "arealight2",
+      "emission": [20.0, 20.0, 20.0]
+    },
+    {
+      "name": "sphere-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "uvsphere-flipcap-uvgrid": {
+    {
+      "name": "uvsphere-flipcap-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "disk-uvgrid": {
+    {
+      "name": "disk-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "uvcylinder-uvgrid": {
+    {
+      "name": "uvcylinder-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "cube-uvgrid": {
+    {
+      "name": "cube-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "sphere": "sphere.ply",
-    "uvsphere-flipcap": "uvsphere-flipcap.ply",
-    "disk": "disk.ply",
-    "uvcylinder": "uvcylinder.ply",
-    "cube": "cube.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
     },
-    "arealight1": {
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "uvsphere-flipcap",
+      "uri": "shapes/uvsphere-flipcap.ply"
+    },
+    {
+      "name": "disk",
+      "uri": "shapes/disk.ply"
+    },
+    {
+      "name": "uvcylinder",
+      "uri": "shapes/uvcylinder.ply"
+    },
+    {
+      "name": "cube",
+      "uri": "shapes/cube.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "arealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ -0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ -0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 1,
+      "material": 1
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ 0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ 0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-uvgrid": {
+    {
+      "name": "sphere-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-uvgrid"
+      "shape": 3,
+      "material": 3
     },
-    "uvsphere-flipcap-uvgrid": {
+    {
+      "name": "uvsphere-flipcap-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "uvsphere-flipcap",
-      "material": "uvsphere-flipcap-uvgrid"
+      "shape": 4,
+      "material": 4
     },
-    "disk-uvgrid": {
-      "shape": "disk",
-      "material": "disk-uvgrid"
+    {
+      "name": "disk-uvgrid",
+      "shape": 5,
+      "material": 5
     },
-    "uvcylinder-uvgrid": {
+    {
+      "name": "uvcylinder-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "uvcylinder",
-      "material": "uvcylinder-uvgrid"
+      "shape": 6,
+      "material": 6
     },
-    "cube-uvgrid": {
+    {
+      "name": "cube-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "cube",
-      "material": "cube-uvgrid"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 7,
+      "material": 7
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/shapes2/shapes2.json b/tests/shapes2/shapes2.json
index 32fd8d385..f7c486167 100644
--- a/tests/shapes2/shapes2.json
+++ b/tests/shapes2/shapes2.json
@@ -2,236 +2,292 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, -0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, 0.936329185962677 ],
-        [ 0.0, 0.574999988079071, 1.399999976158142 ]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, 0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, -0.936329185962677 ],
-        [ 0.0, 0.574999988079071, -1.399999976158142 ]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png",
-    "bumps-displacement": "bumps-displacement.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
     },
-    "arealight1": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    },
+    {
+      "name": "bumps-displacement",
+      "uri": "textures/bumps-displacement.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "arealight2": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight1",
+      "emission": [20.0, 20.0, 20.0]
     },
-    "cube-subdiv-uvgrid": {
+    {
+      "name": "arealight2",
+      "emission": [20.0, 20.0, 20.0]
+    },
+    {
+      "name": "cube-subdiv-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "suzanne-subdiv-plastic-sharp": {
+    {
+      "name": "suzanne-subdiv-plastic-sharp",
       "type": "glossy",
-      "color": [ 0.5, 0.5, 0.699999988079071 ],
+      "color": [0.5, 0.5, 0.699999988079071],
       "roughness": 0.009999999776482582
     },
-    "sphere-displaced-matte": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "sphere-displaced-matte",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "teapot-uvgrid": {
+    {
+      "name": "teapot-uvgrid",
       "type": "glossy",
-      "color": [ 1.0, 1.0, 1.0 ],
+      "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "cube-subdiv": "cube-subdiv.ply",
-    "suzanne-subdiv": "suzanne-subdiv.ply",
-    "sphere-displaced": "sphere-displaced.ply",
-    "bunny": "bunny.ply",
-    "teapot": "teapot.ply"
-  },
-  "subdivs": {
-    "sphere-displaced": {
-      "shape": "sphere-displaced",
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    },
+    {
+      "name": "cube-subdiv",
+      "uri": "shapes/cube-subdiv.ply"
+    },
+    {
+      "name": "suzanne-subdiv",
+      "uri": "shapes/suzanne-subdiv.ply"
+    },
+    {
+      "name": "sphere-displaced",
+      "uri": "shapes/sphere-displaced.ply"
+    },
+    {
+      "name": "bunny",
+      "uri": "shapes/bunny.ply"
+    },
+    {
+      "name": "teapot",
+      "uri": "shapes/teapot.ply"
+    }
+  ],
+  "subdivs": [
+    {
+      "name": "sphere-displaced",
+      "shape": 5,
       "datafile": "sphere-displaced.obj",
       "catmullclark": true,
       "smooth": true,
       "displacement": 0.02500000037252903,
-      "displacement_tex": "bumps-displacement"
+      "displacement_tex": 3,
+      "uri": "sphere-displaced.obj"
     },
-    "suzanne-subdiv": {
-      "shape": "suzanne-subdiv",
+    {
+      "name": "suzanne-subdiv",
+      "shape": 4,
       "datafile": "suzanne-subdiv.obj",
       "subdivisions": 2,
       "catmullclark": true,
-      "smooth": true
+      "smooth": true,
+      "uri": "suzanne-subdiv.obj"
     },
-    "cube-subdiv": {
-      "shape": "cube-subdiv",
+    {
+      "name": "cube-subdiv",
+      "shape": 3,
       "datafile": "cube-subdiv.obj",
       "subdivisions": 4,
-      "catmullclark": true
+      "catmullclark": true,
+      "uri": "cube-subdiv.obj"
     }
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
     },
-    "arealight1": {
+    {
+      "name": "arealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ -0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ -0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 1,
+      "material": 1
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ 0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ 0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
+      "shape": 2,
+      "material": 2
     },
-    "cube-subdiv-uvgrid": {
+    {
+      "name": "cube-subdiv-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "cube-subdiv",
-      "material": "cube-subdiv-uvgrid"
+      "shape": 3,
+      "material": 3
     },
-    "suzanne-subdiv-plastic-sharp": {
+    {
+      "name": "suzanne-subdiv-plastic-sharp",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "suzanne-subdiv",
-      "material": "suzanne-subdiv-plastic-sharp"
+      "shape": 4,
+      "material": 4
     },
-    "sphere-displaced-matte": {
-      "shape": "sphere-displaced",
-      "material": "sphere-displaced-matte"
+    {
+      "name": "sphere-displaced-matte",
+      "shape": 5,
+      "material": 5
     },
-    "bunny-uvgrid": {
+    {
+      "name": "bunny-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "bunny",
-      "material": "bunny-uvgrid"
+      "shape": 6,
+      "material": 6
     },
-    "teapot-uvgrid": {
+    {
+      "name": "teapot-uvgrid",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "teapot",
-      "material": "teapot-uvgrid"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 7,
+      "material": 7
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/shapes3/shapes3.json b/tests/shapes3/shapes3.json
index bdbc1c257..1958d4223 100644
--- a/tests/shapes3/shapes3.json
+++ b/tests/shapes3/shapes3.json
@@ -2,226 +2,272 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, -0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, 0.936329185962677 ],
-        [ 0.0, 0.574999988079071, 1.399999976158142 ]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [ -1.0, 0.0, 0.0 ],
-        [ 0.0, 0.936329185962677, 0.3511234223842621 ],
-        [ 0.0, 0.3511234223842621, -0.936329185962677 ],
-        [ 0.0, 0.574999988079071, -1.399999976158142 ]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [ 0.8151804208755493, -0.0, 0.579207181930542 ],
-        [ 0.16660168766975403, 0.9577393531799316, -0.23447643220424652 ],
-        [ -0.5547295212745667, 0.28763750195503235, 0.7807304263114929 ],
-        [ -0.75, 0.4000000059604645, 0.8999999761581421 ]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png"
-  },
-  "materials": {
-    "floor": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
-      "color_tex": "floor"
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
+      "color_tex": 1
     },
-    "arealight1": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight1",
+      "emission": [20.0, 20.0, 20.0]
     },
-    "arealight2": {
-      "emission": [ 20.0, 20.0, 20.0 ]
+    {
+      "name": "arealight2",
+      "emission": [20.0, 20.0, 20.0]
     },
-    "sphere-matte": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "sphere-matte",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairball1-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairball1-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairball2-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairball2-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairball3-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairball3-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairballi1-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairballi1-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairballi2-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairballi2-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     },
-    "hairballi3-hair": {
-      "color": [ 0.699999988079071, 0.699999988079071, 0.699999988079071 ],
+    {
+      "name": "hairballi3-hair",
+      "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
       "roughness": 1.0
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "sphere": "sphere.ply",
-    "hairball1": "hairball1.ply",
-    "hairball2": "hairball2.ply",
-    "hairball3": "hairball3.ply",
-    "hairballi": "hairballi.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
+    },
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
     },
-    "arealight1": {
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "hairball1",
+      "uri": "shapes/hairball1.ply"
+    },
+    {
+      "name": "hairball2",
+      "uri": "shapes/hairball2.ply"
+    },
+    {
+      "name": "hairball3",
+      "uri": "shapes/hairball3.ply"
+    },
+    {
+      "name": "hairballi",
+      "uri": "shapes/hairballi.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "arealight1",
       "frame": [
-        [ 0.8944271802902222, -0.0, 0.4472135901451111 ],
-        [ 0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ -0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ -0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 1,
+      "material": 1
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [ 0.8944271802902222, 0.0, -0.4472135901451111 ],
-        [ -0.27562475204467773, 0.7874992489814758, -0.5512495040893555 ],
-        [ 0.3521803617477417, 0.6163156628608704, 0.7043607234954834 ],
-        [ 0.4000000059604645, 0.800000011920929, 0.800000011920929 ]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-matte": {
+    {
+      "name": "sphere-matte",
       "frame": [
-        [ 0.5, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.4000000059604645, 0.0, 0.0 ]
+        0.5, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-matte"
+      "shape": 3,
+      "material": 3
     },
-    "hairball1-hair": {
+    {
+      "name": "hairball1-hair",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "hairball1",
-      "material": "hairball1-hair"
+      "shape": 4,
+      "material": 4
     },
-    "hairball2-hair": {
-      "shape": "hairball2",
-      "material": "hairball2-hair"
+    {
+      "name": "hairball2-hair",
+      "shape": 5,
+      "material": 5
     },
-    "hairball3-hair": {
+    {
+      "name": "hairball3-hair",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "hairball3",
-      "material": "hairball3-hair"
+      "shape": 6,
+      "material": 6
     },
-    "hairballi1-hair": {
+    {
+      "name": "hairballi1-hair",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ -0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "hairballi",
-      "material": "hairballi1-hair"
+      "shape": 7,
+      "material": 7
     },
-    "hairballi2-hair": {
-      "shape": "hairballi",
-      "material": "hairballi2-hair"
+    {
+      "name": "hairballi2-hair",
+      "shape": 7,
+      "material": 8
     },
-    "hairballi3-hair": {
+    {
+      "name": "hairballi3-hair",
       "frame": [
-        [ 1.0, 0.0, 0.0 ],
-        [ 0.0, 1.0, 0.0 ],
-        [ 0.0, 0.0, 1.0 ],
-        [ 0.20000000298023224, 0.0, 0.0 ]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "hairballi",
-      "material": "hairballi3-hair"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [ 0.5, 0.5, 0.5 ],
-      "emission_tex": "sky"
+      "shape": 7,
+      "material": 9
     }
-  }
-}
\ No newline at end of file
+  ]
+}
diff --git a/tests/shapes4/shapes4.json b/tests/shapes4/shapes4.json
index 9e0551739..0c22041e7 100644
--- a/tests/shapes4/shapes4.json
+++ b/tests/shapes4/shapes4.json
@@ -2,215 +2,262 @@
   "asset": {
     "copyright": "Model by Fabio Pellacini from github.com/~xelatihy/yocto-gl",
     "generator": "Yocto/GL - https://github.com/xelatihy/yocto-gl",
-    "version": "4.1"
+    "version": "4.2"
   },
-  "cameras": {
-    "default": {
+  "cameras": [
+    {
+      "name": "default",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "front": {
+    {
+      "name": "front",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, -0.3511234223842621],
-        [0.0, 0.3511234223842621, 0.936329185962677],
-        [0.0, 0.574999988079071, 1.399999976158142]
+        1.0, 0.0, 0.0, 0.0, 0.936329185962677, -0.3511234223842621, 0.0,
+        0.3511234223842621, 0.936329185962677, 0.0, 0.574999988079071,
+        1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "back": {
+    {
+      "name": "back",
       "frame": [
-        [-1.0, 0.0, 0.0],
-        [0.0, 0.936329185962677, 0.3511234223842621],
-        [0.0, 0.3511234223842621, -0.936329185962677],
-        [0.0, 0.574999988079071, -1.399999976158142]
+        -1.0, 0.0, 0.0, 0.0, 0.936329185962677, 0.3511234223842621, 0.0,
+        0.3511234223842621, -0.936329185962677, 0.0, 0.574999988079071,
+        -1.399999976158142
       ],
       "aspect": 3.0,
       "focus": 1.4952006340026855
     },
-    "perspective-sharp": {
+    {
+      "name": "perspective-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "perspective-dof": {
+    {
+      "name": "perspective-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.02500000037252903
     },
-    "orthographic-sharp": {
+    {
+      "name": "orthographic-sharp",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133
     },
-    "orthographic-dof": {
+    {
+      "name": "orthographic-dof",
       "frame": [
-        [0.8151804208755493, -0.0, 0.579207181930542],
-        [0.16660168766975403, 0.9577393531799316, -0.23447643220424652],
-        [-0.5547295212745667, 0.28763750195503235, 0.7807304263114929],
-        [-0.75, 0.4000000059604645, 0.8999999761581421]
+        0.8151804208755493, -0.0, 0.579207181930542, 0.16660168766975403,
+        0.9577393531799316, -0.23447643220424652, -0.5547295212745667,
+        0.28763750195503235, 0.7807304263114929, -0.75, 0.4000000059604645,
+        0.8999999761581421
       ],
       "orthographic": true,
       "aspect": 2.4000000953674316,
       "focus": 1.2168092727661133,
       "aperture": 0.019999999552965164
     }
-  },
-  "textures": {
-    "sky": "sky.hdr",
-    "floor": "floor.png",
-    "uvgrid": "uvgrid.png"
-  },
-  "materials": {
-    "floor": {
+  ],
+  "environments": [
+    {
+      "name": "sky",
+      "emission": [0.5, 0.5, 0.5],
+      "emission_tex": 0
+    }
+  ],
+  "textures": [
+    {
+      "name": "sky",
+      "uri": "textures/sky.hdr"
+    },
+    {
+      "name": "floor",
+      "uri": "textures/floor.png"
+    },
+    {
+      "name": "uvgrid",
+      "uri": "textures/uvgrid.png"
+    }
+  ],
+  "materials": [
+    {
+      "name": "floor",
       "color": [0.699999988079071, 0.699999988079071, 0.699999988079071],
-      "color_tex": "floor"
+      "color_tex": 1
     },
-    "arealight1": {
+    {
+      "name": "arealight1",
       "emission": [20.0, 20.0, 20.0]
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "emission": [20.0, 20.0, 20.0]
     },
-    "sphere-uvgrid": {
+    {
+      "name": "sphere-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "points-uvgrid": {
+    {
+      "name": "points-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "thickpoints-uvgrid": {
+    {
+      "name": "thickpoints-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "lines-uvgrid": {
+    {
+      "name": "lines-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     },
-    "thicklines-uvgrid": {
+    {
+      "name": "thicklines-uvgrid",
       "type": "glossy",
       "color": [1.0, 1.0, 1.0],
       "roughness": 0.10000000149011612,
-      "color_tex": "uvgrid"
+      "color_tex": 2
     }
-  },
-  "shapes": {
-    "floor": "floor.ply",
-    "arealight1": "arealight1.ply",
-    "arealight2": "arealight2.ply",
-    "sphere": "sphere.ply",
-    "points-grid": "points-grid.ply",
-    "thickpoints-grid": "thickpoints-grid.ply",
-    "lines-grid": "lines-grid.ply",
-    "thicklines-grid": "thicklines-grid.ply"
-  },
-  "instances": {
-    "floor": {
-      "shape": "floor",
-      "material": "floor"
+  ],
+  "shapes": [
+    {
+      "name": "floor",
+      "uri": "shapes/floor.ply"
+    },
+    {
+      "name": "arealight1",
+      "uri": "shapes/arealight1.ply"
     },
-    "arealight1": {
+    {
+      "name": "arealight2",
+      "uri": "shapes/arealight2.ply"
+    },
+    {
+      "name": "sphere",
+      "uri": "shapes/sphere.ply"
+    },
+    {
+      "name": "points-grid",
+      "uri": "shapes/points-grid.ply"
+    },
+    {
+      "name": "thickpoints-grid",
+      "uri": "shapes/thickpoints-grid.ply"
+    },
+    {
+      "name": "lines-grid",
+      "uri": "shapes/lines-grid.ply"
+    },
+    {
+      "name": "thicklines-grid",
+      "uri": "shapes/thicklines-grid.ply"
+    }
+  ],
+  "instances": [
+    {
+      "name": "floor",
+      "shape": 0,
+      "material": 0
+    },
+    {
+      "name": "arealight1",
       "frame": [
-        [0.8944271802902222, -0.0, 0.4472135901451111],
-        [0.27562475204467773, 0.7874992489814758, -0.5512495040893555],
-        [-0.3521803617477417, 0.6163156628608704, 0.7043607234954834],
-        [-0.4000000059604645, 0.800000011920929, 0.800000011920929]
+        0.8944271802902222, -0.0, 0.4472135901451111, 0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, -0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, -0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight1",
-      "material": "arealight1"
+      "shape": 1,
+      "material": 1
     },
-    "arealight2": {
+    {
+      "name": "arealight2",
       "frame": [
-        [0.8944271802902222, 0.0, -0.4472135901451111],
-        [-0.27562475204467773, 0.7874992489814758, -0.5512495040893555],
-        [0.3521803617477417, 0.6163156628608704, 0.7043607234954834],
-        [0.4000000059604645, 0.800000011920929, 0.800000011920929]
+        0.8944271802902222, 0.0, -0.4472135901451111, -0.27562475204467773,
+        0.7874992489814758, -0.5512495040893555, 0.3521803617477417,
+        0.6163156628608704, 0.7043607234954834, 0.4000000059604645,
+        0.800000011920929, 0.800000011920929
       ],
-      "shape": "arealight2",
-      "material": "arealight2"
+      "shape": 2,
+      "material": 2
     },
-    "sphere-uvgrid": {
+    {
+      "name": "sphere-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "sphere",
-      "material": "sphere-uvgrid"
+      "shape": 3,
+      "material": 3
     },
-    "points-uvgrid": {
+    {
+      "name": "points-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [-0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, -0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "points-grid",
-      "material": "points-uvgrid"
+      "shape": 4,
+      "material": 4
     },
-    "thickpoints-uvgrid": {
-      "shape": "thickpoints-grid",
-      "material": "thickpoints-uvgrid"
+    {
+      "name": "thickpoints-uvgrid",
+      "shape": 5,
+      "material": 5
     },
-    "lines-uvgrid": {
+    {
+      "name": "lines-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.20000000298023224, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.20000000298023224, 0.0,
+        0.0
       ],
-      "shape": "lines-grid",
-      "material": "lines-uvgrid"
+      "shape": 6,
+      "material": 6
     },
-    "thicklines-uvgrid": {
+    {
+      "name": "thicklines-uvgrid",
       "frame": [
-        [1.0, 0.0, 0.0],
-        [0.0, 1.0, 0.0],
-        [0.0, 0.0, 1.0],
-        [0.4000000059604645, 0.0, 0.0]
+        1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.4000000059604645, 0.0,
+        0.0
       ],
-      "shape": "thicklines-grid",
-      "material": "thicklines-uvgrid"
-    }
-  },
-  "environments": {
-    "sky": {
-      "emission": [0.5, 0.5, 0.5],
-      "emission_tex": "sky"
+      "shape": 7,
+      "material": 7
     }
-  }
+  ]
 }