Implement lightmaps.

Cargo.toml

@@ -828,6 +828,17 @@ description = "Showcases wireframe rendering"
 category = "3D Rendering"
 wasm = false
 
+[[example]]
+name = "lightmaps"
+path = "examples/3d/lightmaps.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.lightmaps]
+name = "Lightmaps"
+description = "Displays the Cornell Box with lightmaps"
+category = "3D Rendering"
+wasm = false
+
 [[example]]
 name = "no_prepass"
 path = "tests/3d/no_prepass.rs"

assets/shaders/animate_shader.wgsl

@@ -32,7 +32,7 @@ fn fragment(in: VertexOutput) -> @location(0) vec4<f32> {
     let t_1 = sin(globals.time * speed) * 0.5 + 0.5;
     let t_2 = cos(globals.time * speed);
 
-    let distance_to_center = distance(in.uv, vec2<f32>(0.5)) * 1.4;
+    let distance_to_center = distance(in.uv_a, vec2<f32>(0.5)) * 1.4;
 
     // blending is done in a perceptual color space: https://bottosson.github.io/posts/oklab/
     let red = vec3<f32>(0.627955, 0.224863, 0.125846);

assets/shaders/array_texture.wgsl

@@ -20,7 +20,7 @@ fn fragment(
     // the material members
     var pbr_input: PbrInput = pbr_input_new();
 
-    pbr_input.material.base_color = textureSample(my_array_texture, my_array_texture_sampler, mesh.uv, layer);
+    pbr_input.material.base_color = textureSample(my_array_texture, my_array_texture_sampler, mesh.uv_a, layer);
 #ifdef VERTEX_COLORS
     pbr_input.material.base_color = pbr_input.material.base_color * mesh.color;
 #endif
@@ -43,7 +43,7 @@ fn fragment(
         mesh.world_tangent,
 #endif
 #endif
-        mesh.uv,
+        mesh.uv_a,
         view.mip_bias,
     );
     pbr_input.V = fns::calculate_view(mesh.world_position, pbr_input.is_orthographic);

assets/shaders/custom_material.wgsl

@@ -14,5 +14,5 @@ struct CustomMaterial {
 fn fragment(
     mesh: VertexOutput,
 ) -> @location(0) vec4<f32> {
-    return material.color * textureSample(base_color_texture, base_color_sampler, mesh.uv) * COLOR_MULTIPLIER;
+    return material.color * textureSample(base_color_texture, base_color_sampler, mesh.uv_a) * COLOR_MULTIPLIER;
 }

assets/shaders/texture_binding_array.wgsl

@@ -10,8 +10,8 @@ fn fragment(
     mesh: VertexOutput,
 ) -> @location(0) vec4<f32> {
     // Select the texture to sample from using non-uniform uv coordinates
-    let coords = clamp(vec2<u32>(mesh.uv * 4.0), vec2<u32>(0u), vec2<u32>(3u));
+    let coords = clamp(vec2<u32>(mesh.uv_a * 4.0), vec2<u32>(0u), vec2<u32>(3u));
     let index = coords.y * 4u + coords.x;
-    let inner_uv = fract(mesh.uv * 4.0);
+    let inner_uv = fract(mesh.uv_a * 4.0);
     return textureSample(textures[index], nearest_sampler, inner_uv);
 }

assets/shaders/tonemapping_test_patterns.wgsl

@@ -46,7 +46,7 @@ fn continuous_hue(uv: vec2<f32>) -> vec3<f32> {
 fn fragment(
     in: VertexOutput,
 ) -> @location(0) vec4<f32> {
-    var uv = in.uv;
+    var uv = in.uv_a;
     var out = vec3(0.0);
     if uv.y > 0.5 {
         uv.y = 1.0 - uv.y;

crates/bevy_pbr/src/lib.rs

@@ -87,6 +87,8 @@ pub const PBR_PREPASS_FUNCTIONS_SHADER_HANDLE: Handle<Shader> =
 pub const PBR_DEFERRED_TYPES_HANDLE: Handle<Shader> = Handle::weak_from_u128(3221241127431430599);
 pub const PBR_DEFERRED_FUNCTIONS_HANDLE: Handle<Shader> = Handle::weak_from_u128(72019026415438599);
 pub const RGB9E5_FUNCTIONS_HANDLE: Handle<Shader> = Handle::weak_from_u128(2659010996143919192);
+pub const LIGHTMAPS_SHADER_HANDLE: Handle<Shader> =
+    Handle::weak_from_u128(285484768317531991932943596447919767152);
 
 /// Sets up the entire PBR infrastructure of bevy.
 pub struct PbrPlugin {
@@ -200,6 +202,12 @@ impl Plugin for PbrPlugin {
             "render/parallax_mapping.wgsl",
             Shader::from_wgsl
         );
+        load_internal_asset!(
+            app,
+            LIGHTMAPS_SHADER_HANDLE,
+            "render/lightmaps.wgsl",
+            Shader::from_wgsl
+        );
 
         app.register_asset_reflect::<StandardMaterial>()
             .register_type::<AlphaMode>()
@@ -238,6 +246,7 @@ impl Plugin for PbrPlugin {
                 FogPlugin,
                 ExtractResourcePlugin::<DefaultOpaqueRendererMethod>::default(),
                 ExtractComponentPlugin::<ShadowFilteringMethod>::default(),
+                LightmapPlugin,
             ))
             .configure_sets(
                 PostUpdate,

crates/bevy_pbr/src/material.rs

@@ -1,7 +1,8 @@
 use crate::{
-    render, AlphaMode, DrawMesh, DrawPrepass, EnvironmentMapLight, MeshPipeline, MeshPipelineKey,
-    PrepassPipelinePlugin, PrepassPlugin, RenderMeshInstances, ScreenSpaceAmbientOcclusionSettings,
-    SetMeshBindGroup, SetMeshViewBindGroup, Shadow, ShadowFilteringMethod,
+    render, AlphaMode, DrawMesh, DrawPrepass, EnvironmentMapLight, Lightmap, MeshPipeline,
+    MeshPipelineKey, PrepassPipelinePlugin, PrepassPlugin, RenderMeshInstances,
+    ScreenSpaceAmbientOcclusionSettings, SetMeshBindGroup, SetMeshViewBindGroup, Shadow,
+    ShadowFilteringMethod,
 };
 use bevy_app::{App, Plugin};
 use bevy_asset::{Asset, AssetApp, AssetEvent, AssetId, AssetServer, Assets, Handle};
@@ -442,6 +443,7 @@ pub fn queue_material_meshes<M: Material>(
     mut render_mesh_instances: ResMut<RenderMeshInstances>,
     render_material_instances: Res<RenderMaterialInstances<M>>,
     images: Res<RenderAssets<Image>>,
+    lightmaps: Query<&Lightmap>,
     mut views: Query<(
         &ExtractedView,
         &VisibleEntities,
@@ -565,6 +567,10 @@ pub fn queue_material_meshes<M: Material>(
             }
             mesh_key |= alpha_mode_pipeline_key(material.properties.alpha_mode);
 
+            if lightmaps.contains(*visible_entity) {
+                mesh_key |= MeshPipelineKey::LIGHTMAPPED;
+            }
+
             let pipeline_id = pipelines.specialize(
                 &pipeline_cache,
                 &material_pipeline,

crates/bevy_pbr/src/prepass/mod.rs

@@ -428,7 +428,7 @@ where
         }
 
         if layout.contains(Mesh::ATTRIBUTE_UV_0) {
-            shader_defs.push("VERTEX_UVS".into());
+            shader_defs.push("VERTEX_UVS_A".into());
             vertex_attributes.push(Mesh::ATTRIBUTE_UV_0.at_shader_location(1));
         }
 

crates/bevy_pbr/src/prepass/prepass.wgsl

@@ -58,9 +58,9 @@ fn vertex(vertex_no_morph: Vertex) -> VertexOutput {
     out.position.z = min(out.position.z, 1.0);
 #endif // DEPTH_CLAMP_ORTHO
 
-#ifdef VERTEX_UVS
-    out.uv = vertex.uv;
-#endif // VERTEX_UVS
+#ifdef VERTEX_UVS_A
+    out.uv_a = vertex.uv_a;
+#endif // VERTEX_UVS_A
 
 #ifdef NORMAL_PREPASS_OR_DEFERRED_PREPASS
 #ifdef SKINNED

crates/bevy_pbr/src/prepass/prepass_io.wgsl

@@ -6,7 +6,7 @@ struct Vertex {
     @builtin(instance_index) instance_index: u32,
     @location(0) position: vec3<f32>,
 
-#ifdef VERTEX_UVS
+#ifdef VERTEX_UVS_A
     @location(1) uv: vec2<f32>,
 #endif
 
@@ -36,7 +36,7 @@ struct VertexOutput {
     // and `frag coord` when used as a fragment stage input
     @builtin(position) position: vec4<f32>,
 
-#ifdef VERTEX_UVS
+#ifdef VERTEX_UVS_A
     @location(0) uv: vec2<f32>,
 #endif
 

crates/bevy_pbr/src/render/forward_io.wgsl

@@ -8,10 +8,12 @@ struct Vertex {
 #ifdef VERTEX_NORMALS
     @location(1) normal: vec3<f32>,
 #endif
-#ifdef VERTEX_UVS
-    @location(2) uv: vec2<f32>,
+#ifdef VERTEX_UVS_A
+    @location(2) uv_a: vec2<f32>,
+#endif
+#ifdef VERTEX_UVS_B
+    @location(3) uv_b: vec2<f32>,
 #endif
-// (Alternate UVs are at location 3, but they're currently unused here.)
 #ifdef VERTEX_TANGENTS
     @location(4) tangent: vec4<f32>,
 #endif
@@ -33,17 +35,20 @@ struct VertexOutput {
     @builtin(position) position: vec4<f32>,
     @location(0) world_position: vec4<f32>,
     @location(1) world_normal: vec3<f32>,
-#ifdef VERTEX_UVS
-    @location(2) uv: vec2<f32>,
+#ifdef VERTEX_UVS_A
+    @location(2) uv_a: vec2<f32>,
+#endif
+#ifdef VERTEX_UVS_B
+    @location(3) uv_b: vec2<f32>,
 #endif
 #ifdef VERTEX_TANGENTS
-    @location(3) world_tangent: vec4<f32>,
+    @location(4) world_tangent: vec4<f32>,
 #endif
 #ifdef VERTEX_COLORS
-    @location(4) color: vec4<f32>,
+    @location(5) color: vec4<f32>,
 #endif
 #ifdef VERTEX_OUTPUT_INSTANCE_INDEX
-    @location(5) @interpolate(flat) instance_index: u32,
+    @location(6) @interpolate(flat) instance_index: u32,
 #endif
 }