Partial support for Lightmapper on WebGPU

examples/src/examples/graphics/lights-baked-a-o.mjs

@@ -417,5 +417,4 @@ export class LightsBakedAOExample {
     static CATEGORY = 'Graphics';
     static controls = controls;
     static example = example;
-    static WEBGPU_ENABLED = false; // house is just gray
 }

examples/src/examples/graphics/lights-baked.mjs

@@ -152,5 +152,4 @@ async function example({ canvas, deviceType, glslangPath, twgslPath }) {
 export class LightsBakedExample {
     static CATEGORY = 'Graphics';
     static example = example;
-    static WEBGPU_ENABLED = false; // house is black
 }

src/framework/lightmapper/lightmapper.js

@@ -30,7 +30,6 @@ import {
     FOG_NONE,
     LIGHTTYPE_DIRECTIONAL, LIGHTTYPE_OMNI, LIGHTTYPE_SPOT,
     PROJECTION_ORTHOGRAPHIC, PROJECTION_PERSPECTIVE,
-    SHADER_FORWARDHDR,
     SHADERDEF_DIRLM, SHADERDEF_LM, SHADERDEF_LMAMBIENT,
     MASK_BAKE, MASK_AFFECT_LIGHTMAPPED, MASK_AFFECT_DYNAMIC,
     SHADOWUPDATE_REALTIME, SHADOWUPDATE_THISFRAME
@@ -46,6 +45,7 @@ import { LightmapCache } from '../../scene/graphics/lightmap-cache.js';
 import { LightmapFilters } from './lightmap-filters.js';
 import { BlendState } from '../../platform/graphics/blend-state.js';
 import { DepthState } from '../../platform/graphics/depth-state.js';
+import { RenderPassLightmapper } from './render-pass-lightmapper.js';
 
 const MAX_LIGHTMAP_SIZE = 2048;
 
@@ -228,7 +228,8 @@ class Lightmapper {
         const material = new StandardMaterial();
         material.name = `lmMaterial-pass:${pass}-ambient:${addAmbient}`;
         material.chunks.APIVersion = CHUNKAPI_1_65;
-        material.chunks.transformVS = '#define UV1LAYOUT\n' + shaderChunks.transformVS; // draw UV1
+        const transformDefines = '#define UV1LAYOUT\n' + (device.isWebGPU ? '#define UV1LAYOUT_FLIP\n' : '');
+        material.chunks.transformVS = transformDefines + shaderChunks.transformVS; // draw into UV1 texture space
 
         if (pass === PASS_COLOR) {
             let bakeLmEndChunk = shaderChunksLightmapper.bakeLmEndPS; // encode to RGBM
@@ -514,11 +515,6 @@ class Lightmapper {
     bake(nodes, mode = BAKE_COLORDIR) {
 
         const device = this.device;
-        if (device.isWebGPU) {
-            Debug.warnOnce('Lightmapper is not supported on WebGPU, skipping.');
-            return;
-        }
-
         const startTime = now();
 
         // update skybox
@@ -854,12 +850,24 @@ class Lightmapper {
 
             if (light.type === LIGHTTYPE_DIRECTIONAL) {
                 this.renderer._shadowRendererDirectional.cull(light, comp, this.camera, casters);
+
+                const shadowPass = this.renderer._shadowRendererDirectional.getLightRenderPass(light, this.camera);
+                shadowPass?.render();
+
             } else {
+
+                // TODO: lightmapper on WebGPU does not yet support spot and omni shadows
+                if (this.device.isWebGPU) {
+                    Debug.warnOnce('Lightmapper on WebGPU does not yet support spot and omni shadows.');
+                    return true;
+                }
+
                 this.renderer._shadowRendererLocal.cull(light, comp, casters);
-            }
 
-            const insideRenderPass = false;
-            this.renderer.shadowRenderer.render(light, this.camera, insideRenderPass);
+                // TODO: this needs to used render passes to work on WebGPU
+                const insideRenderPass = false;
+                this.renderer.shadowRenderer.render(light, this.camera, insideRenderPass);
+            }
         }
 
         return true;
@@ -1078,24 +1086,17 @@ class Lightmapper {
                         // update shader
                         this.renderer.updateShaders(rcv);
 
-                        // ping-ponging output
-                        this.renderer.setCamera(this.camera, tempRT, true);
-
+                        // render receivers to the tempRT
                         if (pass === PASS_DIR) {
                             this.constantBakeDir.setValue(bakeLight.light.bakeDir ? 1 : 0);
                         }
 
-                        // prepare clustered lighting
-                        if (clusteredLightingEnabled) {
-                            this.worldClusters.activate();
-                        }
-
-                        this.renderer._forwardTime = 0;
-                        this.renderer._shadowMapTime = 0;
-
-                        this.renderer.renderForward(this.camera, rcv, lightArray, SHADER_FORWARDHDR);
-
-                        device.updateEnd();
+                        const renderPass = new RenderPassLightmapper(device, this.renderer, this.camera,
+                                                                     clusteredLightingEnabled ? this.worldClusters : null,
+                                                                     rcv, lightArray);
+                        renderPass.init(tempRT);
+                        renderPass.render();
+                        renderPass.destroy();
 
                         // #if _PROFILER
                         this.stats.shadowMapTime += this.renderer._shadowMapTime;

src/framework/lightmapper/render-pass-lightmapper.js

@@ -0,0 +1,55 @@
+import { DebugGraphics } from '../../platform/graphics/debug-graphics.js';
+import { RenderPass } from '../../platform/graphics/render-pass.js';
+import { SHADER_FORWARDHDR } from '../../scene/constants.js';
+
+/**
+ * A render pass implementing rendering of mesh instance receivers for light-mapper.
+ *
+ * @ignore
+ */
+class RenderPassLightmapper extends RenderPass {
+    /** @type {import('../../platform/graphics/bind-group.js').BindGroup[]} */
+    viewBindGroups = [];
+
+    constructor(device, renderer, camera, worldClusters, receivers, lightArray) {
+        super(device);
+        this.renderer = renderer;
+        this.camera = camera;
+        this.worldClusters = worldClusters;
+        this.receivers = receivers;
+        this.lightArray = lightArray;
+    }
+
+    destroy() {
+        this.viewBindGroups.forEach((bg) => {
+            bg.defaultUniformBuffer.destroy();
+            bg.destroy();
+        });
+        this.viewBindGroups.length = 0;
+    }
+
+    execute() {
+        const device = this.device;
+        DebugGraphics.pushGpuMarker(device, 'Lightmapper');
+
+        const { renderer, camera, receivers, renderTarget, worldClusters, lightArray } = this;
+
+        // prepare clustered lighting
+        if (worldClusters) {
+            worldClusters.activate();
+        }
+
+        renderer.setCameraUniforms(camera, renderTarget);
+        if (device.supportsUniformBuffers) {
+            renderer.setupViewUniformBuffers(this.viewBindGroups, renderer.viewUniformFormat, renderer.viewBindGroupFormat, 1);
+        }
+
+        renderer._forwardTime = 0;
+        renderer._shadowMapTime = 0;
+        renderer.renderForward(camera, receivers, lightArray, SHADER_FORWARDHDR);
+
+        DebugGraphics.popGpuMarker(device);
+    }
+}
+
+export { RenderPassLightmapper };

src/scene/shader-lib/chunks/common/vert/transform.js

@@ -115,6 +115,9 @@ vec4 getPosition() {
     vec4 screenPos;
     #ifdef UV1LAYOUT
     screenPos = vec4(vertex_texCoord1.xy * 2.0 - 1.0, 0.5, 1);
+        #ifdef UV1LAYOUT_FLIP
+        screenPos.y *= -1.0;
+        #endif
     #else
     #ifdef SCREENSPACE
     screenPos = posW;

src/scene/shader-lib/chunks/lightmapper/frag/bilateralDeNoise.js

@@ -45,7 +45,7 @@ uniform float kernel[MSIZE];
 
 void main(void) {
 
-    vec4 pixelRgbm = texture2D(source, vUv0);
+    vec4 pixelRgbm = texture2DLodEXT(source, vUv0, 0.0);
 
     // lightmap specific optimization - skip pixels that were not baked
     // this also allows dilate filter that work on the output of this to work correctly, as it depends on .a being zero
@@ -72,7 +72,7 @@ void main(void) {
 
             // sample the pixel with offset
             vec2 coord = vUv0 + vec2(float(i), float(j)) * pixelOffset;
-            vec4 rgbm = texture2D(source, coord);
+            vec4 rgbm = texture2DLodEXT(source, coord, 0.0);
 
             // lightmap - only use baked pixels
             if (rgbm.a > 0.0) {

src/scene/shader-lib/chunks/lightmapper/frag/dilate.js

@@ -6,15 +6,15 @@ uniform sampler2D source;
 uniform vec2 pixelOffset;
 
 void main(void) {
-    vec4 c = texture2D(source, vUv0);
-    c = c.a>0.0? c : texture2D(source, vUv0 - pixelOffset);
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(0, -pixelOffset.y));
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(pixelOffset.x, -pixelOffset.y));
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(-pixelOffset.x, 0));
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(pixelOffset.x, 0));
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(-pixelOffset.x, pixelOffset.y));
-    c = c.a>0.0? c : texture2D(source, vUv0 + vec2(0, pixelOffset.y));
-    c = c.a>0.0? c : texture2D(source, vUv0 + pixelOffset);
+    vec4 c = texture2DLodEXT(source, vUv0, 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 - pixelOffset, 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(0, -pixelOffset.y), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(pixelOffset.x, -pixelOffset.y), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(-pixelOffset.x, 0), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(pixelOffset.x, 0), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(-pixelOffset.x, pixelOffset.y), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + vec2(0, pixelOffset.y), 0.0);
+    c = c.a>0.0? c : texture2DLodEXT(source, vUv0 + pixelOffset, 0.0);
     gl_FragColor = c;
 }
 `;