Refactor the way lit-shader integrates lightmapping

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

@@ -73,7 +73,6 @@ import immediateLineVS from './internal/vert/immediateLine.js';
 // import lightDirPointPS from './lit/frag/lightDirPoint.js';
 // import lightingPS from './lit/frag/lighting/lighting.js';
 // import lightmapAddPS from './lit/frag/lightmapAdd.js';
-// import lightmapDirAddPS from './lit/frag/lightmapDirAdd.js';
 // import lightmapDirPS from './standard/frag/lightmapDir.js';
 // import lightmapSinglePS from './standard/frag/lightmapSingle.js';
 // import lightSpecularAnisoGGXPS from './lit/frag/lightSpecularAnisoGGX.js';
@@ -285,7 +284,6 @@ const shaderChunksWGSL = {
     // lightDirPointPS,
     // lightingPS,
     // lightmapAddPS,
-    // lightmapDirAddPS,
     // lightmapDirPS,
     // lightmapSinglePS,
     // lightSpecularAnisoGGXPS,

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

@@ -75,7 +75,6 @@ const chunkVersions = {
     fresnelSchlickPS: CHUNKAPI_1_65,
     iridescenceDiffractionPS: CHUNKAPI_1_65,
     lightmapAddPS: CHUNKAPI_1_65,
-    lightmapDirAddPS: CHUNKAPI_1_65,
     refractionCubePS: CHUNKAPI_1_70,
     refractionDynamicPS: CHUNKAPI_1_70
 };
@@ -120,7 +119,8 @@ const removedChunks = {
     endVS: CHUNKAPI_2_6,
     baseVS: CHUNKAPI_2_6,
     baseNineSlicedVS: CHUNKAPI_2_6,
-    viewNormalVS: CHUNKAPI_2_6
+    viewNormalVS: CHUNKAPI_2_6,
+    lightmapDirAddPS: 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

@@ -73,7 +73,6 @@ import lightDiffuseLambertPS from './lit/frag/lightDiffuseLambert.js';
 import lightDirPointPS from './lit/frag/lightDirPoint.js';
 import lightingPS from './lit/frag/lighting/lighting.js';
 import lightmapAddPS from './lit/frag/lightmapAdd.js';
-import lightmapDirAddPS from './lit/frag/lightmapDirAdd.js';
 import lightmapDirPS from './standard/frag/lightmapDir.js';
 import lightmapSinglePS from './standard/frag/lightmapSingle.js';
 import lightSpecularAnisoGGXPS from './lit/frag/lightSpecularAnisoGGX.js';
@@ -285,7 +284,6 @@ const shaderChunks = {
     lightDirPointPS,
     lightingPS,
     lightmapAddPS,
-    lightmapDirAddPS,
     lightmapDirPS,
     lightmapSinglePS,
     lightSpecularAnisoGGXPS,

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

@@ -14,6 +14,42 @@ void addLightMap(
     float iridescenceIntensity
 #endif
 ) {
-    dDiffuseLight += lightmap;
+
+    // directional lightmap
+    #if defined(LIT_SPECULAR) && defined(LIT_DIR_LIGHTMAP)
+
+        if (dot(dir, dir) < 0.0001) {
+                dDiffuseLight += lightmap;
+        } else {
+            float vlight = saturate(dot(dir, -vertexNormal));
+            float flight = saturate(dot(dir, -worldNormal));
+            float nlight = (flight / max(vlight, 0.01)) * 0.5;
+
+            dDiffuseLight += lightmap * nlight * 2.0;
+
+            vec3 halfDir = normalize(-dir + viewDir);
+            vec3 specularLight = lightmap * getLightSpecular(halfDir, reflectionDir, worldNormal, viewDir, dir, gloss, tbn);
+
+            #ifdef LIT_SPECULAR_FRESNEL
+
+                specularLight *= 
+                    getFresnel(dot(viewDir, halfDir), 
+                    gloss, 
+                    specularity
+                #if defined(LIT_IRIDESCENCE)
+                    , iridescenceFresnel,
+                    iridescenceIntensity
+                #endif
+                    );
+            #endif
+
+            dSpecularLight += specularLight;
+        }
+
+    #else // non-directional lightmap
+
+        dDiffuseLight += lightmap;
+
+    #endif
 }
 `;

src/scene/shader-lib/programs/lit-shader.js

@@ -520,6 +520,8 @@ class LitShader {
         this.fDefineSet(options.useCubeMapRotation, 'CUBEMAP_ROTATION');
         this.fDefineSet(options.occludeSpecularFloat, 'LIT_OCCLUDE_SPECULAR_FLOAT');
         this.fDefineSet(options.twoSidedLighting, 'LIT_TWO_SIDED_LIGHTING');
+        this.fDefineSet(options.lightMapEnabled, 'LIT_LIGHTMAP');
+        this.fDefineSet(options.dirLightMapEnabled, 'LIT_DIR_LIGHTMAP');
 
         // FRAGMENT SHADER INPUTS: UNIFORMS
 
@@ -711,12 +713,14 @@ class LitShader {
             }
         }
 
-        func.append(chunks.combinePS);
+        func.append(`
 
-        // lightmap support
-        if (options.lightMapEnabled) {
-            func.append((options.useSpecular && options.dirLightMapEnabled) ? chunks.lightmapDirAddPS : chunks.lightmapAddPS);
-        }
+            #include "combinePS"
+
+            #ifdef LIT_LIGHTMAP
+                #include "lightmapAddPS"
+            #endif
+        `);
 
         const addAmbient = !options.lightMapEnabled || options.lightMapWithoutAmbient;
 
@@ -873,23 +877,25 @@ class LitShader {
             backend.append('    occludeDiffuse(litArgs_ao);');
         }
 
-        if (options.lightMapEnabled) {
-            backend.append(`    addLightMap(
-                litArgs_lightmap, 
-                litArgs_lightmapDir, 
-                litArgs_worldNormal, 
-                dViewDirW, 
-                dReflDirW, 
-                litArgs_gloss, 
-                litArgs_specularity, 
-                dVertexNormalW,
-                dTBN
-            #if defined(LIT_IRIDESCENCE)
-                , iridescenceFresnel,
-                litArgs_iridescence_intensity
+        backend.append(`
+            #ifdef LIT_LIGHTMAP
+                addLightMap(
+                    litArgs_lightmap, 
+                    litArgs_lightmapDir, 
+                    litArgs_worldNormal, 
+                    dViewDirW, 
+                    dReflDirW, 
+                    litArgs_gloss, 
+                    litArgs_specularity, 
+                    dVertexNormalW,
+                    dTBN
+                #if defined(LIT_IRIDESCENCE)
+                    , iridescenceFresnel,
+                    litArgs_iridescence_intensity
+                #endif
+                );
             #endif
-                );`);
-        }
+        `);
 
         if (this.lighting || this.reflections) {
             if (this.reflections) {