(0.12 regression) Can't play animation in more than one scene

[ostwilkens]

Bevy version

0.12

[Optional] Relevant system information

2023-11-11T21:29:02.719346Z  INFO bevy_winit::system: Creating new window "App" (0v0)
2023-11-11T21:29:03.010640Z  INFO bevy_render::renderer: AdapterInfo { name: "NVIDIA GeForce RTX 2070", vendor: 4318, device: 7938, device_type: DiscreteGpu, driver: "NVIDIA", driver_info: "536.67", backend: Vulkan }
2023-11-11T21:29:03.653577Z  INFO bevy_diagnostic::system_information_diagnostics_plugin::internal: SystemInfo { os: "Windows 10 Education", kernel: "19045", cpu: "Intel(R) Core(TM) i5-10600K CPU @ 4.10GHz", core_count: "6", memory: "31.9 GiB" }

What you did

Refer to the same Handle<AnimationClip> on two AnimationPlayers

use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .add_systems(Update, setup_scene_once_loaded)
        .run();
}

#[derive(Resource)]
struct Animation(Handle<AnimationClip>);

fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.insert_resource(Animation(asset_server.load("foxes.glb#Animation0")));
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(0.0, 0.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
    commands.spawn(SceneBundle {
        scene: asset_server.load("foxes.glb#Scene0"),
        ..default()
    });
    commands.spawn(SceneBundle {
        scene: asset_server.load("foxes.glb#Scene1"),
        ..default()
    });
}

fn setup_scene_once_loaded(
    animation: Res<Animation>,
    mut players: Query<&mut AnimationPlayer, Added<AnimationPlayer>>,
) {
    for mut player in &mut players {
        player.play(animation.0.clone()).repeat();
    }
}

foxes.glb
minimal reproduction project.zip

What went wrong

• what were you expecting?
  I was expecting both scenes to animate
• what actually happened?
  Only the first animates, and the log is filled with
  WARN bevy_animation: Animation player on 58v0 did not match any entity paths.

Additional information

The issue appeared after migrating from 0.11 to 0.12

[idanarye]

Aren't Scene0 and Scene1 different scenes? Are you sure Animation0 fits them both?

What happens when you try to play it only on Scene1?

[ostwilkens]

Aren't Scene0 and Scene1 different scenes? Are you sure Animation0 fits them both?

Yes, Scene1 is a clone of Scene0.

What happens when you try to play it only on Scene1?

I can't believe I didn't try this! It fails as well. That's even more weird, seeing as the scenes are identical.
This means the title isn't accurate, but I have no theories about what's happening. I will have to do more testing.

For context, my game uses a single .glb containing multiple rigged scenes, which use the same animations (as they are all humanoids).

[nicopap]

FYI you can edit the title by using the "edit" button right next to the title.

This might be caused by the root entity name's not matching. This was removed, as it was considered a bug.

• See check root node for animations #9407 and AnimationPlayer can play unrelated AnimationClips  #8357

Consider using identical names for your scenes. If it's not possible in your 3D editor (for example, in blender), consider using https://github.com/nicopap/bevy-scene-hook to swap the name when the scene is spawned.

[ostwilkens]

@nicopap Thank you for checking in on this issue!

I was confused as to how an entity name is relevant, as my animations (Actions) in blender AFAIK aren't connected to a specific scene. I just store them in the file.

However, you prompted me to look into the structure of the exported GLTF file. And apparently, all animations are re-exported for each scene!

So I guess this issue was born out of my lack of GLTF understanding, combined with a bevy bug, which I saw as a feature 😀

I will load each separate animation for the corresponding character, and it should work. Closing.