9cc7e7c080
* Save 16 bytes per vertex by calculating tangents in the shader at runtime, rather than storing them in the vertex data. * Based on https://jcgt.org/published/0009/03/04, https://www.jeremyong.com/graphics/2023/12/16/surface-gradient-bump-mapping. * Fixed visbuffer resolve to use the updated algorithm that flips ddy correctly * Added some more docs about meshlet material limitations, and some TODOs about transforming UV coordinates for the future.  For testing add a normal map to the bunnies with StandardMaterial like below, and then test that on both main and this PR (make sure to download the correct bunny for each). Results should be mostly identical. ```rust normal_map_texture: Some(asset_server.load_with_settings( "textures/BlueNoise-Normal.png", |settings: &mut ImageLoaderSettings| settings.is_srgb = false, )), ```
136 lines
6.3 KiB
WebGPU Shading Language
136 lines
6.3 KiB
WebGPU Shading Language
#define_import_path bevy_pbr::meshlet_bindings
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#import bevy_pbr::mesh_types::Mesh
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#import bevy_render::view::View
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#import bevy_pbr::prepass_bindings::PreviousViewUniforms
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struct PackedMeshletVertex {
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a: vec4<f32>,
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b: vec4<f32>,
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}
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struct MeshletVertex {
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position: vec3<f32>,
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normal: vec3<f32>,
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uv: vec2<f32>,
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}
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fn unpack_meshlet_vertex(packed: PackedMeshletVertex) -> MeshletVertex {
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var vertex: MeshletVertex;
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vertex.position = packed.a.xyz;
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vertex.normal = vec3(packed.a.w, packed.b.xy);
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vertex.uv = packed.b.zw;
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return vertex;
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}
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struct Meshlet {
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start_vertex_id: u32,
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start_index_id: u32,
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vertex_count: u32,
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triangle_count: u32,
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}
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struct MeshletBoundingSpheres {
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self_culling: MeshletBoundingSphere,
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self_lod: MeshletBoundingSphere,
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parent_lod: MeshletBoundingSphere,
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}
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struct MeshletBoundingSphere {
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center: vec3<f32>,
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radius: f32,
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}
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struct DispatchIndirectArgs {
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x: atomic<u32>,
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y: u32,
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z: u32,
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}
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struct DrawIndirectArgs {
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vertex_count: u32,
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instance_count: atomic<u32>,
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first_vertex: u32,
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first_instance: u32,
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}
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#ifdef MESHLET_FILL_CLUSTER_BUFFERS_PASS
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var<push_constant> cluster_count: u32;
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@group(0) @binding(0) var<storage, read> meshlet_instance_meshlet_counts_prefix_sum: array<u32>; // Per entity instance
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@group(0) @binding(1) var<storage, read> meshlet_instance_meshlet_slice_starts: array<u32>; // Per entity instance
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@group(0) @binding(2) var<storage, read_write> meshlet_cluster_instance_ids: array<u32>; // Per cluster
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@group(0) @binding(3) var<storage, read_write> meshlet_cluster_meshlet_ids: array<u32>; // Per cluster
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#endif
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#ifdef MESHLET_CULLING_PASS
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var<push_constant> meshlet_raster_cluster_rightmost_slot: u32;
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@group(0) @binding(0) var<storage, read> meshlet_cluster_meshlet_ids: array<u32>; // Per cluster
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@group(0) @binding(1) var<storage, read> meshlet_bounding_spheres: array<MeshletBoundingSpheres>; // Per meshlet
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@group(0) @binding(2) var<storage, read> meshlet_cluster_instance_ids: array<u32>; // Per cluster
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@group(0) @binding(3) var<storage, read> meshlet_instance_uniforms: array<Mesh>; // Per entity instance
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@group(0) @binding(4) var<storage, read> meshlet_view_instance_visibility: array<u32>; // 1 bit per entity instance, packed as a bitmask
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@group(0) @binding(5) var<storage, read_write> meshlet_second_pass_candidates: array<atomic<u32>>; // 1 bit per cluster , packed as a bitmask
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@group(0) @binding(6) var<storage, read_write> meshlet_software_raster_indirect_args: DispatchIndirectArgs; // Single object shared between all workgroups/clusters/triangles
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@group(0) @binding(7) var<storage, read_write> meshlet_hardware_raster_indirect_args: DrawIndirectArgs; // Single object shared between all workgroups/clusters/triangles
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@group(0) @binding(8) var<storage, read_write> meshlet_raster_clusters: array<u32>; // Single object shared between all workgroups/clusters/triangles
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@group(0) @binding(9) var depth_pyramid: texture_2d<f32>; // From the end of the last frame for the first culling pass, and from the first raster pass for the second culling pass
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@group(0) @binding(10) var<uniform> view: View;
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@group(0) @binding(11) var<uniform> previous_view: PreviousViewUniforms;
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fn should_cull_instance(instance_id: u32) -> bool {
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let bit_offset = instance_id % 32u;
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let packed_visibility = meshlet_view_instance_visibility[instance_id / 32u];
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return bool(extractBits(packed_visibility, bit_offset, 1u));
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}
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// TODO: Load 4x per workgroup instead of once per thread?
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fn cluster_is_second_pass_candidate(cluster_id: u32) -> bool {
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let packed_candidates = meshlet_second_pass_candidates[cluster_id / 32u];
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let bit_offset = cluster_id % 32u;
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return bool(extractBits(packed_candidates, bit_offset, 1u));
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}
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#endif
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#ifdef MESHLET_VISIBILITY_BUFFER_RASTER_PASS
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@group(0) @binding(0) var<storage, read> meshlet_cluster_meshlet_ids: array<u32>; // Per cluster
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@group(0) @binding(1) var<storage, read> meshlets: array<Meshlet>; // Per meshlet
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@group(0) @binding(2) var<storage, read> meshlet_indices: array<u32>; // Many per meshlet
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@group(0) @binding(3) var<storage, read> meshlet_vertex_ids: array<u32>; // Many per meshlet
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@group(0) @binding(4) var<storage, read> meshlet_vertex_data: array<PackedMeshletVertex>; // Many per meshlet
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@group(0) @binding(5) var<storage, read> meshlet_cluster_instance_ids: array<u32>; // Per cluster
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@group(0) @binding(6) var<storage, read> meshlet_instance_uniforms: array<Mesh>; // Per entity instance
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@group(0) @binding(7) var<storage, read> meshlet_raster_clusters: array<u32>; // Single object shared between all workgroups/clusters/triangles
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@group(0) @binding(8) var<storage, read> meshlet_software_raster_cluster_count: u32;
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#ifdef MESHLET_VISIBILITY_BUFFER_RASTER_PASS_OUTPUT
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@group(0) @binding(9) var<storage, read_write> meshlet_visibility_buffer: array<atomic<u64>>; // Per pixel
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#else
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@group(0) @binding(9) var<storage, read_write> meshlet_visibility_buffer: array<atomic<u32>>; // Per pixel
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#endif
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@group(0) @binding(10) var<uniform> view: View;
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// TODO: Load only twice, instead of 3x in cases where you load 3 indices per thread?
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fn get_meshlet_index(index_id: u32) -> u32 {
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let packed_index = meshlet_indices[index_id / 4u];
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let bit_offset = (index_id % 4u) * 8u;
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return extractBits(packed_index, bit_offset, 8u);
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}
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#endif
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#ifdef MESHLET_MESH_MATERIAL_PASS
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@group(1) @binding(0) var<storage, read> meshlet_visibility_buffer: array<u64>; // Per pixel
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@group(1) @binding(1) var<storage, read> meshlet_cluster_meshlet_ids: array<u32>; // Per cluster
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@group(1) @binding(2) var<storage, read> meshlets: array<Meshlet>; // Per meshlet
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@group(1) @binding(3) var<storage, read> meshlet_indices: array<u32>; // Many per meshlet
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@group(1) @binding(4) var<storage, read> meshlet_vertex_ids: array<u32>; // Many per meshlet
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@group(1) @binding(5) var<storage, read> meshlet_vertex_data: array<PackedMeshletVertex>; // Many per meshlet
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@group(1) @binding(6) var<storage, read> meshlet_cluster_instance_ids: array<u32>; // Per cluster
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@group(1) @binding(7) var<storage, read> meshlet_instance_uniforms: array<Mesh>; // Per entity instance
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// TODO: Load only twice, instead of 3x in cases where you load 3 indices per thread?
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fn get_meshlet_index(index_id: u32) -> u32 {
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let packed_index = meshlet_indices[index_id / 4u];
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let bit_offset = (index_id % 4u) * 8u;
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return extractBits(packed_index, bit_offset, 8u);
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}
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#endif
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