GLTF rendering is no longer predictable after 0.13

[Shatur]

Bevy version

0.13

[Optional] Relevant system information

OS: ArchLinux
CPU: 32 × AMD Ryzen 9 5950X 16-Core Processor

What you did

I rendering to texture in order to have preview for models in my game.

In 0.12 I discovered a bug #10688 that has been fixed in #10745.

What went wrong

But after update to 0.13 it looks like it has been reintroduced. I have the same problem, sometimes it renders the asset, sometimes not.

Additional information

Here is the minimal example to reproduce: assets_render.zip.
If you disable multi-threaded feature, it will work as expected.

With the following changes the code compiles on 0.12 and works as expected with multi-threaded feature on:

diff --git a/Cargo.toml b/Cargo.toml
index 0d88782..6955489 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-bevy = { version = "0.13", default-features = false, features = [
+bevy = { version = "0.12", default-features = false, features = [
   "bevy_gltf",
   "bevy_ui",
   "bevy_sprite",
diff --git a/src/main.rs b/src/main.rs
index 190bc1c..7b5cd2f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -12,7 +12,7 @@ fn main() {
     App::new()
         .insert_resource(AmbientLight {
             color: Color::WHITE,
-            brightness: 1000.0,
+            brightness: 1.0,
         })
         .add_plugins((
             DefaultPlugins.set(LogPlugin {
diff --git a/src/preview.rs b/src/preview.rs
index 7718258..3b55e72 100644
--- a/src/preview.rs
+++ b/src/preview.rs
@@ -14,7 +14,7 @@ pub(super) struct PreviewPlugin;
 
 impl Plugin for PreviewPlugin {
     fn build(&self, app: &mut App) {
-        app.init_state::<PreviewState>()
+        app.add_state::<PreviewState>()
             .add_systems(Startup, Self::spawn_camera_system)
             .add_systems(OnEnter(PreviewState::Inactive), Self::deactivation_system)
             .add_systems(
@@ -143,6 +143,7 @@ const PREVIEW_RENDER_LAYER: RenderLayers = RenderLayers::layer(1);
 #[derive(Bundle)]
 struct PreviewCameraBundle {
     name: Name,
+    ui_camera_config: UiCameraConfig,
     preview_camera: PreviewCamera,
     render_layer: RenderLayers,
     camera_bundle: Camera3dBundle,
@@ -153,6 +154,7 @@ impl Default for PreviewCameraBundle {
     fn default() -> Self {
         Self {
             name: "Preview camera".into(),
+            ui_camera_config: UiCameraConfig { show_ui: false },
             preview_camera: PreviewCamera,
             render_layer: PREVIEW_RENDER_LAYER,
             camera_bundle: Camera3dBundle {

[BD103]

I was unable to reproduce this on my machine, using the zipfile linked.

2024-02-23T19:33:07.795597Z  INFO log: Adapter Metal AdapterInfo { name: "Apple M1", vendor: 0, device: 0, device_type: IntegratedGpu, driver: "", driver_info: "", backend: Metal }    
2024-02-23T19:33:07.796343Z  INFO bevy_render::renderer: AdapterInfo { name: "Apple M1", vendor: 0, device: 0, device_type: IntegratedGpu, driver: "", driver_info: "", backend: Metal }
2024-02-23T19:33:08.136412Z  INFO bevy_winit::system: Creating new window "App" (0v1)
2024-02-23T19:33:08.165192Z  INFO bevy_diagnostic::system_information_diagnostics_plugin::internal: SystemInfo { os: "MacOS 14.2.1 ", kernel: "23.2.0", cpu: "Apple M1", core_count: "8", memory: "16.0 GiB" }

How many times did you have to run the program in order to see the incorrect behavior? All of the images rendered correctly for me.

[Shatur]

Happens 100% of the time for me (I just downloaded the archive and compiled it from scratch):

Added system information to the issue. Looks like we have different OSes. I also have a lot of cores (32).

[BD103]

Odd, there must be some architectural differences that makes the bug more common on your system. Let's wait for someone else to weigh in and test it...

[mockersf]

This is due to asynchronous pipeline compilation, which is disabled on macOS or without feature multi-threaded

What's happening is:

• gltf is loaded
• you try to display it
• displaying it trigger the pipeline compilation
• if the pipeline is compiled fast enough, or was compiled for a previously loaded asset, the gltf will be displayed. otherwise, nothing happens

This is most of the times not a problem because Bevy keeps trying to render things every frame, but in your case you're only rendering it once

[rparrett]

(async pipeline compilation can be disabled with this setting on RenderPlugin.)

Or you can try to make sure all pipelines are compiled before advancing from a loading state.

[Shatur]

Thank you a lot, disabling async pipeline compilation fixed the issue.

[Shatur]

Or you can try to make sure all pipelines are compiled before advancing from a loading state.

How can I do so?

[rparrett]

How can I do so?

It's a bit of a pain. You need to create a "loading scene" that has every permutation of material properties or whatever so that all pipelines are created.

And then in the render app, check that status of all pipelines in PipelineCache.

There are advantages though -- on the web, pipeline compilation hangs the app and causes audio weirdness.

This tiny plugin can help a bit: https://github.com/rparrett/bevy_pipelines_ready.

See also: #10871

[Shatur]

Thanks!

[cart]

I think an important missing feature is a reasonable way to detect when everything in a scene is "fully ready to render".