render-assets-diagnostics.md

---

title: Render Assets diagnostics
authors: ["@hukasu"]
pull_requests: [19311]

---

Goals

Create diagnostics plugins MeshAllocatorDiagnosticPlugin, MaterialAllocatorDiagnosticPlugin, RenderAssetDiagnosticPlugin, and ErasedRenderAssetDiagnosticPlugin, that collect measurements related to MeshAllocators, MaterialBindGroupAllocator, RenderAssets, and ErasedRenderAssets respectively.

MeshAllocatorDiagnosticPlugin and MaterialDiagnosticPlugin measure the number of slabs, the total size of memory allocated by the slabs, and the number of objects allocated in the slabs. Only bindless materials use slabs for their allocations, non-bindless materials return 0 for all of them.

RenderAssetDiagnosticsPlugin<RA> and ErasedAssetDiagnosticsPlugin<ERA> measure the number of assets in RenderAssets<RA> and ErasedRenderAssets<ERA::ErasedAsset>. ErasedAssetDiagnosticsPlugin<ERA> will report the same number of assets for all ERA that share the same ERA::ErasedAsset.

Showcase

app.add_plugins(DefaultPlugins)
    .add_plugins((
        MeshAllocatorDiagnosticPlugin,
        MaterialAllocatorDiagnosticPlugin::<StandardMaterial>::default(),
        RenderAssetDiagnosticPlugin::<RenderMesh>::new(" render meshes"),
        RenderAssetDiagnosticPlugin::<GpuImage>::new(" gpu images"),
        // ImageMaterial is the name of the manual material used on the `manual_material` example
        ErasedRenderAssetDiagnosticPlugin::<ImageMaterial>::new(" image materials"),
    ));

If you also have LogDiagnosticsPlugin, the output looks something like this:

INFO bevy_diagnostic: mesh_allocator_allocations                                             :    4.000000 meshes (avg 4.000000 meshes)
INFO bevy_diagnostic: mesh_allocator_slabs                                                   :    4.000000 slabs (avg 4.000000 slabs)
INFO bevy_diagnostic: mesh_allocator_slabs_size                                              : 4194360.000000 bytes (avg 4194360.000000 bytes)
INFO bevy_diagnostic: material_allocator_allocations/bevy_pbr::pbr_material::StandardMaterial:   14.000000 materials (avg 14.000000 materials)
INFO bevy_diagnostic: material_allocator_slabs/bevy_pbr::pbr_material::StandardMaterial      :    1.000000 slabs (avg 1.000000 slabs)
INFO bevy_diagnostic: material_allocator_slabs_size/bevy_pbr::pbr_material::StandardMaterial :  576.000000 bytes (avg 576.000000 bytes)
INFO bevy_diagnostic: render_asset/bevy_render::mesh::RenderMesh                             :    5.000000 render meshes (avg 5.000000 render meshes)
INFO bevy_diagnostic: render_asset/bevy_render::texture::gpu_image::GpuImage                 :   10.000000 gpu images (avg 10.000000 gpu images)
INFO bevy_diagnostic: erased_render_asset/manual_material::ImageMaterial                     :    2.000000 image materials (avg 2.000000 image materials)