Refactor of lit-shader generator, mostly related to the ambient lighting

src/scene/constants.js

@@ -748,44 +748,11 @@ export const specularOcclusionNames = {
     [SPECOCC_GLOSSDEPENDENT]: 'GLOSSDEPENDENT'
 };
 
-/**
- * There is no reflection source.
- *
- * @type {string}
- * @category Graphics
- */
+// reflection source used by the shader generation
 export const REFLECTIONSRC_NONE = 'none';
-
-/**
- * EnvAtlas is used as a source for the reflection.
- *
- * @type {string}
- * @category Graphics
- */
 export const REFLECTIONSRC_ENVATLAS = 'envAtlas';
-
-/**
- * EnvAtlas and high resolution cubemap are used as a source for the reflection.
- *
- * @type {string}
- * @category Graphics
- */
 export const REFLECTIONSRC_ENVATLASHQ = 'envAtlasHQ';
-
-/**
- * Cubemap is used as a source for the reflection.
- *
- * @type {string}
- * @category Graphics
- */
 export const REFLECTIONSRC_CUBEMAP = 'cubeMap';
-
-/**
- * Spheremap is used as a source for the reflection.
- *
- * @type {string}
- * @category Graphics
- */
 export const REFLECTIONSRC_SPHEREMAP = 'sphereMap';
 
 export const reflectionSrcNames = {
@@ -796,6 +763,17 @@ export const reflectionSrcNames = {
     [REFLECTIONSRC_SPHEREMAP]: 'SPHEREMAP'
 };
 
+// ambient source used by the shader generation
+export const AMBIENTSRC_AMBIENTSH = 'ambientSH';
+export const AMBIENTSRC_ENVALATLAS = 'envAtlas';
+export const AMBIENTSRC_CONSTANT = 'constant';
+
+export const ambientSrcNames = {
+    [AMBIENTSRC_AMBIENTSH]: 'AMBIENTSH',
+    [AMBIENTSRC_ENVALATLAS]: 'ENVALATLAS',
+    [AMBIENTSRC_CONSTANT]: 'CONSTANT'
+};
+
 // 16 bits for shader defs
 export const SHADERDEF_NOSHADOW = 1;
 export const SHADERDEF_SKIN = 2;

src/scene/materials/lit-material-options-builder.js

@@ -5,7 +5,8 @@ import {
     SHADERDEF_NOSHADOW, SHADERDEF_TANGENTS, SPRITE_RENDERMODE_SIMPLE,
     SHADERDEF_MORPH_TEXTURE_BASED_INT,
     FOG_NONE,
-    REFLECTIONSRC_NONE, REFLECTIONSRC_ENVATLAS, REFLECTIONSRC_ENVATLASHQ, REFLECTIONSRC_CUBEMAP
+    REFLECTIONSRC_NONE, REFLECTIONSRC_ENVATLAS, REFLECTIONSRC_ENVATLASHQ, REFLECTIONSRC_CUBEMAP,
+    AMBIENTSRC_AMBIENTSH, AMBIENTSRC_ENVALATLAS, AMBIENTSRC_CONSTANT
 } from '../constants.js';
 
 class LitMaterialOptionsBuilder {
@@ -112,13 +113,13 @@ class LitMaterialOptionsBuilder {
 
         // source of environment ambient is as follows:
         if (material.ambientSH) {
-            litOptions.ambientSource = 'ambientSH';
+            litOptions.ambientSource = AMBIENTSRC_AMBIENTSH;
             litOptions.ambientEncoding = null;
         } else if (litOptions.reflectionSource !== REFLECTIONSRC_NONE && scene.envAtlas) {
-            litOptions.ambientSource = 'envAtlas';
+            litOptions.ambientSource = AMBIENTSRC_ENVALATLAS;
             litOptions.ambientEncoding = scene.envAtlas.encoding;
         } else {
-            litOptions.ambientSource = 'constant';
+            litOptions.ambientSource = AMBIENTSRC_CONSTANT;
             litOptions.ambientEncoding = null;
         }
 

src/scene/materials/standard-material-options-builder.js

@@ -13,7 +13,8 @@ import {
     DITHER_NONE,
     SHADERDEF_MORPH_TEXTURE_BASED_INT, SHADERDEF_BATCH,
     FOG_NONE,
-    REFLECTIONSRC_NONE, REFLECTIONSRC_ENVATLAS, REFLECTIONSRC_ENVATLASHQ, REFLECTIONSRC_CUBEMAP, REFLECTIONSRC_SPHEREMAP
+    REFLECTIONSRC_NONE, REFLECTIONSRC_ENVATLAS, REFLECTIONSRC_ENVATLASHQ, REFLECTIONSRC_CUBEMAP, REFLECTIONSRC_SPHEREMAP,
+    AMBIENTSRC_AMBIENTSH, AMBIENTSRC_ENVALATLAS, AMBIENTSRC_CONSTANT
 } from '../constants.js';
 import { _matTex2D } from '../shader-lib/programs/standard.js';
 import { LitMaterialOptionsBuilder } from './lit-material-options-builder.js';
@@ -325,15 +326,15 @@ class StandardMaterialOptionsBuilder {
 
         // source of environment ambient is as follows:
         if (stdMat.ambientSH) {
-            options.litOptions.ambientSource = 'ambientSH';
+            options.litOptions.ambientSource = AMBIENTSRC_AMBIENTSH;
             options.litOptions.ambientEncoding = null;
         } else {
             const envAtlas = stdMat.envAtlas || (stdMat.useSkybox && scene.envAtlas ? scene.envAtlas : null);
             if (envAtlas && !stdMat.sphereMap) {
-                options.litOptions.ambientSource = 'envAtlas';
+                options.litOptions.ambientSource = AMBIENTSRC_ENVALATLAS;
                 options.litOptions.ambientEncoding = envAtlas.encoding;
             } else {
-                options.litOptions.ambientSource = 'constant';
+                options.litOptions.ambientSource = AMBIENTSRC_CONSTANT;
                 options.litOptions.ambientEncoding = null;
             }
         }

src/scene/shader-lib/chunks-wgsl/chunks-wgsl.js

@@ -1,7 +1,5 @@
 // import alphaTestPS from './standard/frag/alphaTest.js';
-// import ambientConstantPS from './lit/frag/ambientConstant.js';
-// import ambientEnvPS from './lit/frag/ambientEnv.js';
-// import ambientSHPS from './lit/frag/ambientSH.js';
+// import ambientPS from './lit/frag/ambient.js';
 // import aoPS from './standard/frag/ao.js';
 // import aoDetailMapPS from './standard/frag/aoDetailMap.js';
 // import aoDiffuseOccPS from './lit/frag/aoDiffuseOcc.js';
@@ -199,9 +197,7 @@ import tonemappingNonePS from './common/frag/tonemapping/tonemappingNone.js';
  */
 const shaderChunksWGSL = {
     // alphaTestPS,
-    // ambientConstantPS,
-    // ambientEnvPS,
-    // ambientSHPS,
+    // ambientPS,
     // aoPS,
     // aoDetailMapPS,
     // aoDiffuseOccPS,

src/scene/shader-lib/chunks/chunk-validation.js

@@ -31,10 +31,6 @@ const chunkVersions = {
 
     // backend
     normalVertexPS: CHUNKAPI_1_55,
-
-    ambientConstantPS: CHUNKAPI_1_62,
-    ambientEnvPS: CHUNKAPI_1_62,
-    ambientSHPS: CHUNKAPI_1_62,
     aoDiffuseOccPS: CHUNKAPI_1_62,
     aoSpecOccPS: CHUNKAPI_2_6,
     clusteredLightPS: CHUNKAPI_1_62,
@@ -126,7 +122,10 @@ const removedChunks = {
     envConstPS: CHUNKAPI_2_6,
     aoSpecOccConstPS: CHUNKAPI_2_6,
     aoSpecOccConstSimplePS: CHUNKAPI_2_6,
-    aoSpecOccSimplePS: CHUNKAPI_2_6
+    aoSpecOccSimplePS: CHUNKAPI_2_6,
+    ambientConstantPS: CHUNKAPI_2_6,
+    ambientEnvPS: CHUNKAPI_2_6,
+    ambientSHPS: CHUNKAPI_2_6
 };
 
 // compare two "major.minor" semantic version strings and return true if a is a smaller version than b.

src/scene/shader-lib/chunks/chunks.js

@@ -1,7 +1,5 @@
 import alphaTestPS from './standard/frag/alphaTest.js';
-import ambientConstantPS from './lit/frag/ambientConstant.js';
-import ambientEnvPS from './lit/frag/ambientEnv.js';
-import ambientSHPS from './lit/frag/ambientSH.js';
+import ambientPS from './lit/frag/ambient.js';
 import aoPS from './standard/frag/ao.js';
 import aoDetailMapPS from './standard/frag/aoDetailMap.js';
 import aoDiffuseOccPS from './lit/frag/aoDiffuseOcc.js';
@@ -199,9 +197,7 @@ import webgpuVS from '../../../platform/graphics/shader-chunks/vert/webgpu.js';
  */
 const shaderChunks = {
     alphaTestPS,
-    ambientConstantPS,
-    ambientEnvPS,
-    ambientSHPS,
+    ambientPS,
     aoPS,
     aoDetailMapPS,
     aoDiffuseOccPS,

src/scene/shader-lib/chunks/common/frag/envAtlas.js

@@ -1,4 +1,8 @@
 export default /* glsl */`
+
+#ifndef _ENVATLAS_INCLUDED_
+#define _ENVATLAS_INCLUDED_
+
 // the envAtlas is fixed at 512 pixels. every equirect is generated with 1 pixel boundary.
 const float atlasSize = 512.0;
 const float seamSize = 1.0 / atlasSize;
@@ -20,4 +24,6 @@ vec2 mapShinyUv(vec2 uv, float level) {
     float t = 1.0 / exp2(level);
     return mapUv(uv, vec4(1.0 - t, 1.0 - t, t, t * 0.5));
 }
+
+#endif
 `;

src/scene/shader-lib/chunks/lit/frag/ambient.js

@@ -0,0 +1,52 @@
+export default /* glsl */`
+
+#ifdef LIT_AMBIENT_SOURCE == AMBIENTSH
+    uniform vec3 ambientSH[9];
+#endif
+
+#if LIT_AMBIENT_SOURCE == ENVALATLAS
+    #include "envAtlasPS"
+
+    #ifndef ENV_ATLAS
+    #define ENV_ATLAS
+    uniform sampler2D texture_envAtlas;
+    #endif
+#endif
+
+void addAmbient(vec3 worldNormal) {
+    #ifdef LIT_AMBIENT_SOURCE == AMBIENTSH
+
+        vec3 n = cubeMapRotate(worldNormal);
+        vec3 color =
+            ambientSH[0] +
+            ambientSH[1] * n.x +
+            ambientSH[2] * n.y +
+            ambientSH[3] * n.z +
+            ambientSH[4] * n.x * n.z +
+            ambientSH[5] * n.z * n.y +
+            ambientSH[6] * n.y * n.x +
+            ambientSH[7] * (3.0 * n.z * n.z - 1.0) +
+            ambientSH[8] * (n.x * n.x - n.y * n.y);
+
+        dDiffuseLight += processEnvironment(max(color, vec3(0.0)));
+
+    #endif
+
+    #if LIT_AMBIENT_SOURCE == ENVALATLAS
+
+        vec3 dir = normalize(cubeMapRotate(worldNormal) * vec3(-1.0, 1.0, 1.0));
+        vec2 uv = mapUv(toSphericalUv(dir), vec4(128.0, 256.0 + 128.0, 64.0, 32.0) / atlasSize);
+
+        vec4 raw = texture2D(texture_envAtlas, uv);
+        vec3 linear = {ambientDecode}(raw);
+        dDiffuseLight += processEnvironment(linear);
+
+    #endif
+
+    #if LIT_AMBIENT_SOURCE == CONSTANT
+
+        dDiffuseLight += light_globalAmbient;
+
+    #endif
+}
+`;