bevy/examples/stress_tests
JMS55 44424391fe
Unload render assets from RAM (#10520)
# Objective
- No point in keeping Meshes/Images in RAM once they're going to be sent
to the GPU, and kept in VRAM. This saves a _significant_ amount of
memory (several GBs) on scenes like bistro.
- References
  - https://github.com/bevyengine/bevy/pull/1782
  - https://github.com/bevyengine/bevy/pull/8624 

## Solution
- Augment RenderAsset with the capability to unload the underlying asset
after extracting to the render world.
- Mesh/Image now have a cpu_persistent_access field. If this field is
RenderAssetPersistencePolicy::Unload, the asset will be unloaded from
Assets<T>.
- A new AssetEvent is sent upon dropping the last strong handle for the
asset, which signals to the RenderAsset to remove the GPU version of the
asset.

---

## Changelog
- Added `AssetEvent::NoLongerUsed` and
`AssetEvent::is_no_longer_used()`. This event is sent when the last
strong handle of an asset is dropped.
- Rewrote the API for `RenderAsset` to allow for unloading the asset
data from the CPU.
- Added `RenderAssetPersistencePolicy`.
- Added `Mesh::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `Image::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `ImageLoaderSettings::cpu_persistent_access`.
- Added `ExrTextureLoaderSettings`.
- Added `HdrTextureLoaderSettings`.

## Migration Guide
- Asset loaders (GLTF, etc) now load meshes and textures without
`cpu_persistent_access`. These assets will be removed from
`Assets<Mesh>` and `Assets<Image>` once `RenderAssets<Mesh>` and
`RenderAssets<Image>` contain the GPU versions of these assets, in order
to reduce memory usage. If you require access to the asset data from the
CPU in future frames after the GLTF asset has been loaded, modify all
dependent `Mesh` and `Image` assets and set `cpu_persistent_access` to
`RenderAssetPersistencePolicy::Keep`.
- `Mesh` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `Image` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `MorphTargetImage::new()` now requires a new `cpu_persistent_access`
parameter. Set it to `RenderAssetPersistencePolicy::Keep` to mimic the
previous behavior.
- `DynamicTextureAtlasBuilder::add_texture()` now requires that the
`TextureAtlas` you pass has an `Image` with `cpu_persistent_access:
RenderAssetPersistencePolicy::Keep`. Ensure you construct the image
properly for the texture atlas.
- The `RenderAsset` trait has significantly changed, and requires
adapting your existing implementations.
  - The trait now requires `Clone`.
- The `ExtractedAsset` associated type has been removed (the type itself
is now extracted).
  - The signature of `prepare_asset()` is slightly different
- A new `persistence_policy()` method is now required (return
RenderAssetPersistencePolicy::Unload to match the previous behavior).
- Match on the new `NoLongerUsed` variant for exhaustive matches of
`AssetEvent`.
2024-01-03 03:31:04 +00:00
..
bevymark.rs Unload render assets from RAM (#10520) 2024-01-03 03:31:04 +00:00
many_animated_sprites.rs Use a consistent scale factor and resolution in stress tests (#10474) 2023-11-09 22:05:32 +00:00
many_buttons.rs Override QueryIter::fold to port Query::for_each perf gains to select Iterator combinators (#6773) 2023-12-01 09:09:55 +00:00
many_cubes.rs Unload render assets from RAM (#10520) 2024-01-03 03:31:04 +00:00
many_foxes.rs Update winit dependency to 0.29 (#10702) 2023-12-21 07:40:47 +00:00
many_gizmos.rs Update winit dependency to 0.29 (#10702) 2023-12-21 07:40:47 +00:00
many_glyphs.rs Rename TextAlignment to JustifyText. (#10854) 2023-12-05 03:00:41 +00:00
many_lights.rs Add clippy::manual_let_else at warn level to lints (#10684) 2023-11-28 04:15:27 +00:00
many_sprites.rs Use a consistent scale factor and resolution in stress tests (#10474) 2023-11-09 22:05:32 +00:00
README.md Add a stress test profile (#6901) 2022-12-20 15:59:41 +00:00
text_pipeline.rs Rename TextAlignment to JustifyText. (#10854) 2023-12-05 03:00:41 +00:00
transform_hierarchy.rs Remove some old references to CoreSet (#9833) 2023-09-18 01:07:11 +00:00
warning_string.txt Added performance warning when running stress test examples in debug mode (#5029) 2022-07-13 19:13:46 +00:00

Stress tests

These examples are used to stress test Bevy's performance in various ways. These should be run with the "stress-test" profile to accurately represent performance in production, otherwise they will run in cargo's default "dev" profile which is very slow.

Example Command

cargo run --profile stress-test --example <EXAMPLE>