Memory leak in EntitySpecializationTicks when a material uses NotShadowCaster #21526
Description
Bevy version and features
0.17.2
What you did
This came out of a longer debugging session I "documented" in a bluesky thread.
EDIT: This has been fixed in #21410. See further down for a case that still leaks memory.
//! Example to reproduce memory leak issue. //! use bevy::{ pbr::{ExtendedMaterial, MaterialExtension}, prelude::*, }; use bevy_render::render_resource::AsBindGroup; fn main() { App::new() .add_plugins(DefaultPlugins) .add_plugins(MaterialPlugin::<MyExtendedMaterial1>::default()) // Issue goes away when only a single material is present. .add_plugins(MaterialPlugin::<MyExtendedMaterial2>::default()) .init_resource::<Handles>() .add_systems(Startup, setup) .add_systems(Update, update) .run(); } #[derive(Resource)] struct Handles(Handle<MyExtendedMaterial1>, Handle<Mesh>); type MyExtendedMaterial1 = ExtendedMaterial<StandardMaterial, MyExtension1>; #[derive(Default, Clone, AsBindGroup, Asset, TypePath)] struct MyExtension1 {} impl MaterialExtension for MyExtension1 {} type MyExtendedMaterial2 = ExtendedMaterial<StandardMaterial, MyExtension2>; #[derive(Default, Clone, AsBindGroup, Asset, TypePath)] struct MyExtension2 {} impl MaterialExtension for MyExtension2 {} impl FromWorld for Handles { fn from_world(world: &mut World) -> Self { let material1_handle = world .resource_mut::<Assets<MyExtendedMaterial1>>() .add(MyExtendedMaterial1::default()); let mesh_handle = world.resource_mut::<Assets<Mesh>>().add(Cuboid::default()); Self(material1_handle, mesh_handle) } } fn update( mut commands: Commands, existing_meshes: Query<Entity, With<MeshMaterial3d<MyExtendedMaterial1>>>, handles: Res<Handles>, ) { dbg!(existing_meshes.count()); const COUNT: usize = 100; for _ in 0..COUNT { commands.spawn((Mesh3d(handles.1.clone()), MeshMaterial3d(handles.0.clone()))); } existing_meshes .iter() .take(COUNT) .for_each(|entity| commands.entity(entity).despawn()); } fn setup(mut commands: Commands) { commands.spawn(( Camera3d::default(), Transform::from_xyz(0.0, 7., 14.0).looking_at(Vec3::new(0., 1., 0.), Vec3::Y), )); }What went wrong
EntitySpecializationTicks and SpecializedMaterialPipelineCache grow with each set of spawned/despawned entities, eventually slowing the systems that use them to a crawl.
Running extract_entities_needs_specialization explicitly after early_sweep_material_instances fixes the leaks.
However
In the presence of entities with a NotShadowCaster component, the EntitySpecializationTicks keep growing:
//! Example to reproduce memory leak issue. //! use bevy::{ light::NotShadowCaster, pbr::{ExtendedMaterial, MaterialExtension}, prelude::*, }; use bevy_render::render_resource::AsBindGroup; fn main() { App::new() .add_plugins(DefaultPlugins) .add_plugins(MaterialPlugin::<MyExtendedMaterial1>::default()) // Issue goes away when only a single material is present. .add_plugins(MaterialPlugin::<MyExtendedMaterial2>::default()) .init_resource::<Handles>() .add_systems(Startup, setup) .add_systems(Update, update) .run(); } #[derive(Resource)] struct Handles( Handle<MyExtendedMaterial1>, Handle<MyExtendedMaterial2>, Handle<Mesh>, ); type MyExtendedMaterial1 = ExtendedMaterial<StandardMaterial, MyExtension1>; #[derive(Default, Clone, AsBindGroup, Asset, TypePath)] struct MyExtension1 {} impl MaterialExtension for MyExtension1 {} type MyExtendedMaterial2 = ExtendedMaterial<StandardMaterial, MyExtension2>; #[derive(Default, Clone, AsBindGroup, Asset, TypePath)] struct MyExtension2 {} impl MaterialExtension for MyExtension2 {} impl FromWorld for Handles { fn from_world(world: &mut World) -> Self { let material1_handle = world .resource_mut::<Assets<MyExtendedMaterial1>>() .add(MyExtendedMaterial1::default()); let material2_handle = world .resource_mut::<Assets<MyExtendedMaterial2>>() .add(MyExtendedMaterial2::default()); let mesh_handle = world.resource_mut::<Assets<Mesh>>().add(Cuboid::default()); Self(material1_handle, material2_handle, mesh_handle) } } fn update( mut commands: Commands, existing_meshes1: Query<Entity, With<MeshMaterial3d<MyExtendedMaterial1>>>, existing_meshes2: Query<Entity, With<MeshMaterial3d<MyExtendedMaterial2>>>, handles: Res<Handles>, ) { dbg!(existing_meshes1.count()); dbg!(existing_meshes2.count()); const COUNT: usize = 100; for _ in 0..COUNT { commands.spawn((Mesh3d(handles.2.clone()), MeshMaterial3d(handles.0.clone()))); commands.spawn(( Mesh3d(handles.2.clone()), MeshMaterial3d(handles.1.clone()), NotShadowCaster, )); } existing_meshes1 .iter() .take(COUNT) .for_each(|entity| commands.entity(entity).despawn()); existing_meshes2 .iter() .take(COUNT) .for_each(|entity| commands.entity(entity).despawn()); } fn setup(mut commands: Commands) { commands.spawn(( Camera3d::default(), Transform::from_xyz(0.0, 7., 14.0).looking_at(Vec3::new(0., 1., 0.), Vec3::Y), )); }Additional context
Related: #21410