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