Add sample for testing glTF instancing.

Fixes #1513.

RELEASE_NOTES.md

@@ -5,6 +5,7 @@ A new header is inserted each time a *tag* is created.
 
 ## Next release
 
+- gltfio now supports simple instancing of entire assets.
 - Add missing JavaScript API for `View::setVisibleLayers()`.
 - Add support for DOF with Metal backend.
 - SSAO now has an optional high(er) quality upsampler.

samples/CMakeLists.txt

@@ -221,6 +221,7 @@ if (NOT ANDROID)
     add_demo(depthtesting)
     add_demo(frame_generator)
     add_demo(gltf_viewer)
+    add_demo(gltf_instances)
     add_demo(heightfield)
     add_demo(hellopbr)
     add_demo(hellotriangle)
@@ -240,6 +241,7 @@ if (NOT ANDROID)
     # Sample app specific
     target_link_libraries(frame_generator PRIVATE imageio)
     target_link_libraries(gltf_viewer PRIVATE gltf-resources gltfio)
+    target_link_libraries(gltf_instances PRIVATE gltf-resources gltfio)
     target_link_libraries(hellopbr PRIVATE filameshio suzanne-resources)
     target_link_libraries(sample_cloth PRIVATE filameshio)
     target_link_libraries(sample_normal_map PRIVATE filameshio)
@@ -293,9 +295,3 @@ add_dependencies(filament assets)
 
 add_custom_target(envs DEPENDS ${target_envmaps})
 add_dependencies(filament envs)
-
-add_custom_target(run_gltf_viewer DEPENDS gltf_viewer assets
-        COMMAND gltf_viewer)
-
-add_custom_target(run_material_sandbox DEPENDS material_sandbox assets
-        COMMAND material_sandbox --ibl=venetian_crossroads_2k assets/models/material_sphere/material_sphere.obj)

samples/gltf_instances.cpp

@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define GLTFIO_SIMPLEVIEWER_IMPLEMENTATION
+
+#include <filamentapp/Config.h>
+#include <filamentapp/FilamentApp.h>
+#include <filamentapp/IBL.h>
+
+#include <filament/Engine.h>
+#include <filament/Scene.h>
+#include <filament/Skybox.h>
+#include <filament/View.h>
+
+#include <gltfio/AssetLoader.h>
+#include <gltfio/FilamentAsset.h>
+#include <gltfio/ResourceLoader.h>
+#include <gltfio/SimpleViewer.h>
+
+#include <camutils/Manipulator.h>
+
+#include <getopt/getopt.h>
+
+#include <utils/NameComponentManager.h>
+
+#include <iostream>
+#include <fstream>
+#include <string>
+
+#include <math/mat4.h>
+
+#include "generated/resources/gltf_viewer.h"
+
+using namespace filament;
+using namespace filament::math;
+using namespace gltfio;
+using namespace utils;
+
+static constexpr size_t NUM_INSTANCES = 5;
+
+struct App {
+    Engine* engine;
+    SimpleViewer* viewer;
+    Config config;
+    AssetLoader* loader;
+    FilamentAsset* asset = nullptr;
+    FilamentInstance* instances[NUM_INSTANCES];
+    NameComponentManager* names;
+    MaterialProvider* materials;
+    MaterialSource materialSource = GENERATE_SHADERS;
+    gltfio::ResourceLoader* resourceLoader = nullptr;
+};
+
+static const char* DEFAULT_IBL = "venetian_crossroads_2k";
+
+static void printUsage(char* name) {
+    std::string exec_name(Path(name).getName());
+    std::string usage(
+        "SHOWCASE renders the specified glTF file with instancing\n"
+        "Usage:\n"
+        "    SHOWCASE [options] <gltf path>\n"
+        "Options:\n"
+        "   --help, -h\n"
+        "       Prints this message\n\n"
+        "   --api, -a\n"
+        "       Specify the backend API: opengl (default), vulkan, or metal\n\n"
+        "   --ibl=<path to cmgen IBL>, -i <path>\n"
+        "       Override the built-in IBL\n\n"
+        "   --ubershader, -u\n"
+        "       Enable ubershaders (improves load time, adds shader complexity)\n\n"
+    );
+    const std::string from("SHOWCASE");
+    for (size_t pos = usage.find(from); pos != std::string::npos; pos = usage.find(from, pos)) {
+        usage.replace(pos, from.length(), exec_name);
+    }
+    std::cout << usage;
+}
+
+static int handleCommandLineArguments(int argc, char* argv[], App* app) {
+    static constexpr const char* OPTSTR = "ha:i:u";
+    static const struct option OPTIONS[] = {
+        { "help",         no_argument,       nullptr, 'h' },
+        { "api",          required_argument, nullptr, 'a' },
+        { "ibl",          required_argument, nullptr, 'i' },
+        { "ubershader",   no_argument,       nullptr, 'u' },
+        { nullptr, 0, nullptr, 0 }
+    };
+    int opt;
+    int option_index = 0;
+    while ((opt = getopt_long(argc, argv, OPTSTR, OPTIONS, &option_index)) >= 0) {
+        std::string arg(optarg ? optarg : "");
+        switch (opt) {
+            default:
+            case 'h':
+                printUsage(argv[0]);
+                exit(0);
+            case 'a':
+                if (arg == "opengl") {
+                    app->config.backend = Engine::Backend::OPENGL;
+                } else if (arg == "vulkan") {
+                    app->config.backend = Engine::Backend::VULKAN;
+                } else if (arg == "metal") {
+                    app->config.backend = Engine::Backend::METAL;
+                } else {
+                    std::cerr << "Unrecognized backend. Must be 'opengl'|'vulkan'|'metal'.\n";
+                }
+                break;
+            case 'i':
+                app->config.iblDirectory = arg;
+                break;
+            case 'u':
+                app->materialSource = LOAD_UBERSHADERS;
+                break;
+        }
+    }
+    return optind;
+}
+
+static std::ifstream::pos_type getFileSize(const char* filename) {
+    std::ifstream in(filename, std::ifstream::ate | std::ifstream::binary);
+    return in.tellg();
+}
+
+int main(int argc, char** argv) {
+    App app;
+
+    app.config.title = "glTF Instancing";
+    app.config.iblDirectory = FilamentApp::getRootAssetsPath() + DEFAULT_IBL;
+
+    int optionIndex = handleCommandLineArguments(argc, argv, &app);
+    utils::Path filename;
+    int num_args = argc - optionIndex;
+    if (num_args >= 1) {
+        filename = argv[optionIndex];
+        if (!filename.exists()) {
+            std::cerr << "file " << filename << " not found!" << std::endl;
+            return 1;
+        }
+    }
+
+    auto loadAsset = [&app](utils::Path filename) {
+        // Peek at the file size to allow pre-allocation.
+        long contentSize = static_cast<long>(getFileSize(filename.c_str()));
+        if (contentSize <= 0) {
+            std::cerr << "Unable to open " << filename << std::endl;
+            exit(1);
+        }
+
+        // Consume the glTF file.
+        std::ifstream in(filename.c_str(), std::ifstream::binary | std::ifstream::in);
+        std::vector<uint8_t> buffer(static_cast<unsigned long>(contentSize));
+        if (!in.read((char*) buffer.data(), contentSize)) {
+            std::cerr << "Unable to read " << filename << std::endl;
+            exit(1);
+        }
+
+        // Parse the glTF file and create Filament entities.
+        app.asset = app.loader->createInstancedAsset(buffer.data(), buffer.size(), app.instances,
+            NUM_INSTANCES);
+        buffer.clear();
+        buffer.shrink_to_fit();
+
+        if (!app.asset) {
+            std::cerr << "Unable to parse " << filename << std::endl;
+            exit(1);
+        }
+    };
+
+    auto loadResources = [&app] (utils::Path filename) {
+        // Load external textures and buffers.
+        std::string gltfPath = filename.getAbsolutePath();
+        ResourceConfiguration configuration;
+        configuration.engine = app.engine;
+        configuration.gltfPath = gltfPath.c_str();
+        configuration.normalizeSkinningWeights = true;
+        configuration.recomputeBoundingBoxes = false;
+        if (!app.resourceLoader) {
+            app.resourceLoader = new gltfio::ResourceLoader(configuration);
+        }
+        app.resourceLoader->asyncBeginLoad(app.asset);
+
+        // Load animation data then free the source hierarchy.
+        app.asset->getAnimator();
+        app.asset->releaseSourceData();
+
+        auto ibl = FilamentApp::get().getIBL();
+        if (ibl) {
+            app.viewer->setIndirectLight(ibl->getIndirectLight(), ibl->getSphericalHarmonics());
+        }
+    };
+
+    auto setup = [&](Engine* engine, View* view, Scene* scene) {
+        app.engine = engine;
+        app.names = new NameComponentManager(EntityManager::get());
+        app.viewer = new SimpleViewer(engine, scene, view);
+        app.materials = (app.materialSource == GENERATE_SHADERS) ?
+                createMaterialGenerator(engine) : createUbershaderLoader(engine);
+        app.loader = AssetLoader::create({engine, app.materials, app.names });
+        if (filename.isEmpty()) {
+            app.asset = app.loader->createInstancedAsset(
+                    GLTF_VIEWER_DAMAGEDHELMET_DATA, GLTF_VIEWER_DAMAGEDHELMET_SIZE,
+                    app.instances, NUM_INSTANCES);
+        } else {
+            loadAsset(filename);
+        }
+
+        // Arrange all instances into a circle.
+        auto& tcm = engine->getTransformManager();
+        auto extent = app.asset->getBoundingBox().extent();
+        float max_extent = std::max(std::max(extent.x,  extent.y), extent.z);
+        auto translation = mat4f::translation(float3(max_extent, 0, 0));
+        for (size_t inst = 0; inst < NUM_INSTANCES; ++inst) {
+            FilamentInstance* instance = app.instances[inst];
+            auto transformRoot = tcm.getInstance(instance->getRoot());
+            float theta = inst * 2.0 * M_PI / NUM_INSTANCES;
+            auto rotation = mat4f::rotation(theta, float3(0, 0, 1));
+            tcm.setTransform(transformRoot, rotation * translation);
+        }
+
+        loadResources(filename);
+    };
+
+    auto cleanup = [&app](Engine* engine, View*, Scene*) {
+        app.loader->destroyAsset(app.asset);
+        app.materials->destroyMaterials();
+
+        delete app.viewer;
+        delete app.materials;
+        delete app.names;
+
+        AssetLoader::destroy(&app.loader);
+    };
+
+    auto animate = [&app](Engine* engine, View* view, double now) {
+        app.resourceLoader->asyncUpdateLoad();
+        app.viewer->populateScene(app.asset, true);
+        app.viewer->applyAnimation(now);
+    };
+
+    auto gui = [&app](Engine* engine, View* view) { };
+
+    auto preRender = [&app](Engine* engine, View* view, Scene* scene, Renderer* renderer) { };
+
+    FilamentApp& filamentApp = FilamentApp::get();
+    filamentApp.animate(animate);
+
+    filamentApp.run(app.config, setup, cleanup, gui, preRender);
+
+    return 0;
+}