Add OpenPBR's base_diffuse_roughness material parameter

packages/dev/core/src/Materials/PBR/pbrBaseMaterial.ts

@@ -100,8 +100,10 @@ export class PBRMaterialDefines extends MaterialDefines implements IImageProcess
     public ALBEDODIRECTUV = 0;
     public VERTEXCOLOR = false;
 
-    public BASEWEIGHT = false;
-    public BASEWEIGHTDIRECTUV = 0;
+    public BASE_WEIGHT = false;
+    public BASE_WEIGHTDIRECTUV = 0;
+    public BASE_DIFFUSE_ROUGHNESS = false;
+    public BASE_DIFFUSE_ROUGHNESSDIRECTUV = 0;
 
     public BAKED_VERTEX_ANIMATION_TEXTURE = false;
 
@@ -422,11 +424,17 @@ export abstract class PBRBaseMaterial extends PushMaterial {
     public _albedoTexture: Nullable<BaseTexture> = null;
 
     /**
-     * OpenPBR Base Weight (multiplier to the diffuse and metal lobes).
+     * OpenPBR Base Weight texture (multiplier to the diffuse and metal lobes).
      * @internal
      */
     public _baseWeightTexture: Nullable<BaseTexture> = null;
 
+    /**
+     * OpenPBR Base Diffuse Roughness texture (roughness of the diffuse lobe).
+     * @internal
+     */
+    public _baseDiffuseRoughnessTexture: Nullable<BaseTexture> = null;
+
     /**
      * AKA Occlusion Texture in other nomenclature.
      * @internal
@@ -575,6 +583,13 @@ export abstract class PBRBaseMaterial extends PushMaterial {
      */
     public _baseWeight = 1;
 
+    /**
+     * OpenPBR Base Diffuse Roughness (roughness of the diffuse lobe).
+     * Can also be used to scale the corresponding texture.
+     * @internal
+     */
+    public _baseDiffuseRoughness: Nullable<number> = null;
+
     /**
      * AKA Specular Color in other nomenclature.
      * @internal
@@ -1131,6 +1146,12 @@ export abstract class PBRBaseMaterial extends PushMaterial {
                     }
                 }
 
+                if (this._baseDiffuseRoughnessTexture && MaterialFlags.BaseDiffuseRoughnessTextureEnabled) {
+                    if (!this._baseDiffuseRoughnessTexture.isReadyOrNotBlocking()) {
+                        return false;
+                    }
+                }
+
                 if (this._ambientTexture && MaterialFlags.AmbientTextureEnabled) {
                     if (!this._ambientTexture.isReadyOrNotBlocking()) {
                         return false;
@@ -1443,6 +1464,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             "vAmbientColor",
             "vAlbedoColor",
             "baseWeight",
+            "baseDiffuseRoughness",
             "vReflectivityColor",
             "vMetallicReflectanceFactors",
             "vEmissiveColor",
@@ -1453,6 +1475,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             "pointSize",
             "vAlbedoInfos",
             "vBaseWeightInfos",
+            "vBaseDiffuseRoughnessInfos",
             "vAmbientInfos",
             "vOpacityInfos",
             "vReflectionInfos",
@@ -1469,6 +1492,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             "mBones",
             "albedoMatrix",
             "baseWeightMatrix",
+            "baseDiffuseRoughnessMatrix",
             "ambientMatrix",
             "opacityMatrix",
             "reflectionMatrix",
@@ -1511,6 +1535,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
         const samplers = [
             "albedoSampler",
             "baseWeightSampler",
+            "baseDiffuseRoughnessSampler",
             "reflectivitySampler",
             "ambientSampler",
             "emissiveSampler",
@@ -1647,7 +1672,8 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             }
             if (scene.texturesEnabled) {
                 defines.ALBEDODIRECTUV = 0;
-                defines.BASEWEIGHTDIRECTUV = 0;
+                defines.BASE_WEIGHTDIRECTUV = 0;
+                defines.BASE_DIFFUSE_ROUGHNESSDIRECTUV = 0;
                 defines.AMBIENTDIRECTUV = 0;
                 defines.OPACITYDIRECTUV = 0;
                 defines.EMISSIVEDIRECTUV = 0;
@@ -1670,9 +1696,15 @@ export abstract class PBRBaseMaterial extends PushMaterial {
                 }
 
                 if (this._baseWeightTexture && MaterialFlags.BaseWeightTextureEnabled) {
-                    PrepareDefinesForMergedUV(this._baseWeightTexture, defines, "BASEWEIGHT");
+                    PrepareDefinesForMergedUV(this._baseWeightTexture, defines, "BASE_WEIGHT");
                 } else {
-                    defines.BASEWEIGHT = false;
+                    defines.BASE_WEIGHT = false;
+                }
+
+                if (this._baseDiffuseRoughnessTexture && MaterialFlags.BaseDiffuseRoughnessTextureEnabled) {
+                    PrepareDefinesForMergedUV(this._baseDiffuseRoughnessTexture, defines, "BASE_DIFFUSE_ROUGHNESS");
+                } else {
+                    defines.BASE_DIFFUSE_ROUGHNESS = false;
                 }
 
                 if (this._ambientTexture && MaterialFlags.AmbientTextureEnabled) {
@@ -2024,6 +2056,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
         const ubo = this._uniformBuffer;
         ubo.addUniform("vAlbedoInfos", 2);
         ubo.addUniform("vBaseWeightInfos", 2);
+        ubo.addUniform("vBaseDiffuseRoughnessInfos", 2);
         ubo.addUniform("vAmbientInfos", 4);
         ubo.addUniform("vOpacityInfos", 2);
         ubo.addUniform("vEmissiveInfos", 2);
@@ -2037,6 +2070,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
         ubo.addUniform("vBumpInfos", 3);
         ubo.addUniform("albedoMatrix", 16);
         ubo.addUniform("baseWeightMatrix", 16);
+        ubo.addUniform("baseDiffuseRoughnessMatrix", 16);
         ubo.addUniform("ambientMatrix", 16);
         ubo.addUniform("opacityMatrix", 16);
         ubo.addUniform("emissiveMatrix", 16);
@@ -2050,6 +2084,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
         ubo.addUniform("vReflectionColor", 3);
         ubo.addUniform("vAlbedoColor", 4);
         ubo.addUniform("baseWeight", 1);
+        ubo.addUniform("baseDiffuseRoughness", 1);
         ubo.addUniform("vLightingIntensity", 4);
 
         ubo.addUniform("vReflectionMicrosurfaceInfos", 3);
@@ -2157,6 +2192,11 @@ export abstract class PBRBaseMaterial extends PushMaterial {
                         BindTextureMatrix(this._baseWeightTexture, ubo, "baseWeight");
                     }
 
+                    if (this._baseDiffuseRoughnessTexture && MaterialFlags.BaseDiffuseRoughnessTextureEnabled) {
+                        ubo.updateFloat2("vBaseDiffuseRoughnessInfos", this._baseDiffuseRoughnessTexture.coordinatesIndex, this._baseDiffuseRoughnessTexture.level);
+                        BindTextureMatrix(this._baseDiffuseRoughnessTexture, ubo, "baseDiffuseRoughness");
+                    }
+
                     if (this._ambientTexture && MaterialFlags.AmbientTextureEnabled) {
                         ubo.updateFloat4(
                             "vAmbientInfos",
@@ -2319,6 +2359,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
                 }
 
                 ubo.updateFloat("baseWeight", this._baseWeight);
+                ubo.updateFloat("baseDiffuseRoughness", this._baseDiffuseRoughness);
 
                 // Misc
                 this._lightingInfos.x = this._directIntensity;
@@ -2346,6 +2387,10 @@ export abstract class PBRBaseMaterial extends PushMaterial {
                     ubo.setTexture("baseWeightSampler", this._baseWeightTexture);
                 }
 
+                if (this._baseDiffuseRoughnessTexture && MaterialFlags.BaseDiffuseRoughnessTextureEnabled) {
+                    ubo.setTexture("baseDiffuseRoughnessSampler", this._baseDiffuseRoughnessTexture);
+                }
+
                 if (this._ambientTexture && MaterialFlags.AmbientTextureEnabled) {
                     ubo.setTexture("ambientSampler", this._ambientTexture);
                 }
@@ -2484,6 +2529,10 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             results.push(this._baseWeightTexture);
         }
 
+        if (this._baseDiffuseRoughnessTexture && this._baseDiffuseRoughnessTexture.animations && this._baseDiffuseRoughnessTexture.animations.length > 0) {
+            results.push(this._baseDiffuseRoughnessTexture);
+        }
+
         if (this._ambientTexture && this._ambientTexture.animations && this._ambientTexture.animations.length > 0) {
             results.push(this._ambientTexture);
         }
@@ -2556,6 +2605,10 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             activeTextures.push(this._baseWeightTexture);
         }
 
+        if (this._baseDiffuseRoughnessTexture) {
+            activeTextures.push(this._baseDiffuseRoughnessTexture);
+        }
+
         if (this._ambientTexture) {
             activeTextures.push(this._ambientTexture);
         }
@@ -2621,6 +2674,10 @@ export abstract class PBRBaseMaterial extends PushMaterial {
             return true;
         }
 
+        if (this._baseDiffuseRoughnessTexture === texture) {
+            return true;
+        }
+
         if (this._ambientTexture === texture) {
             return true;
         }
@@ -2701,6 +2758,7 @@ export abstract class PBRBaseMaterial extends PushMaterial {
 
             this._albedoTexture?.dispose();
             this._baseWeightTexture?.dispose();
+            this._baseDiffuseRoughnessTexture?.dispose();
             this._ambientTexture?.dispose();
             this._opacityTexture?.dispose();
             this._reflectionTexture?.dispose();

packages/dev/core/src/Materials/PBR/pbrMaterial.ts

@@ -93,12 +93,19 @@ export class PBRMaterial extends PBRBaseMaterial {
     public albedoTexture: Nullable<BaseTexture>;
 
     /**
-     * OpenPBR Base Weight (multiplier to the diffuse and metal lobes).
+     * OpenPBR Base Weight texture (multiplier to the diffuse and metal lobes).
      */
     @serializeAsTexture()
     @expandToProperty("_markAllSubMeshesAsTexturesDirty")
     public baseWeightTexture: Nullable<BaseTexture>;
 
+    /**
+     * OpenPBR Base Diffuse Roughness texture (roughness of the diffuse lobe).
+     */
+    @serializeAsTexture()
+    @expandToProperty("_markAllSubMeshesAsTexturesDirty")
+    public baseDiffuseRoughnessTexture: Nullable<BaseTexture>;
+
     /**
      * AKA Occlusion Texture in other nomenclature.
      */
@@ -284,6 +291,13 @@ export class PBRMaterial extends PBRBaseMaterial {
     @expandToProperty("_markAllSubMeshesAsTexturesDirty")
     public baseWeight = 1;
 
+    /**
+     * OpenPBR Base Diffuse Roughness (roughness of the diffuse lobe).
+     */
+    @serialize("baseDiffuseRoughness")
+    @expandToProperty("_markAllSubMeshesAsTexturesDirty")
+    public baseDiffuseRoughness = 1;
+
     /**
      * AKA Specular Color in other nomenclature.
      */

packages/dev/core/src/Materials/materialFlags.ts

@@ -38,6 +38,22 @@ export class MaterialFlags {
         AbstractEngine.MarkAllMaterialsAsDirty(Constants.MATERIAL_TextureDirtyFlag);
     }
 
+    private static _BaseDiffuseRoughnessTextureEnabled = true;
+    /**
+     * Is the OpenPBR Base Diffuse Roughness texture enabled in the application.
+     */
+    public static get BaseDiffuseRoughnessTextureEnabled(): boolean {
+        return this._BaseDiffuseRoughnessTextureEnabled;
+    }
+    public static set BaseDiffuseRoughnessTextureEnabled(value: boolean) {
+        if (this._BaseDiffuseRoughnessTextureEnabled === value) {
+            return;
+        }
+
+        this._BaseDiffuseRoughnessTextureEnabled = value;
+        AbstractEngine.MarkAllMaterialsAsDirty(Constants.MATERIAL_TextureDirtyFlag);
+    }
+
     private static _DetailTextureEnabled = true;
     /**
      * Are detail textures enabled in the application.

packages/dev/core/src/Shaders/ShadersInclude/lightFragment.fx

@@ -51,7 +51,7 @@
                         preInfo.attenuation *= computeDirectionalLightFalloff_IES(light{X}.vLightDirection.xyz, preInfo.L, iesLightTexture{X});
                     #else
                         preInfo.attenuation *= computeDirectionalLightFalloff(light{X}.vLightDirection.xyz, preInfo.L, light{X}.vLightDirection.w, light{X}.vLightData.w, light{X}.vLightFalloff.z, light{X}.vLightFalloff.w);
-                    #endif                        
+                    #endif
                 #endif
             #elif defined(POINTLIGHT{X})
                 #ifdef LIGHT_FALLOFF_GLTF{X}
@@ -74,6 +74,7 @@
             #else
                 preInfo.roughness = adjustRoughnessFromLightProperties(roughness, light{X}.vLightSpecular.a, preInfo.lightDistance);
             #endif
+            preInfo.diffuseRoughness = diffuseRoughness;
 
             #ifdef IRIDESCENCE
                 preInfo.iridescenceIntensity = iridescenceIntensity;
@@ -87,6 +88,7 @@
             #elif defined(SS_TRANSLUCENCY)
                 info.diffuse = computeDiffuseAndTransmittedLighting(preInfo, diffuse{X}.rgb, subSurfaceOut.transmittance);
             #else
+                preInfo.roughness = diffuseRoughness;
                 info.diffuse = computeDiffuseLighting(preInfo, diffuse{X}.rgb);
             #endif
 
@@ -129,7 +131,7 @@
                     #endif
 
                     info.clearCoat = computeClearCoatLighting(preInfo, clearcoatOut.clearCoatNormalW, clearcoatOut.clearCoatAARoughnessFactors.x, clearcoatOut.clearCoatIntensity, diffuse{X}.rgb);
-                    
+
                     #ifdef CLEARCOAT_TINT
                         // Absorption
                         absorption = computeClearCoatLightingAbsorption(clearcoatOut.clearCoatNdotVRefract, preInfo.L, clearcoatOut.clearCoatNormalW, clearcoatOut.clearCoatColor, clearcoatOut.clearCoatThickness, clearcoatOut.clearCoatIntensity);
@@ -178,7 +180,7 @@
 
     #ifdef SHADOW{X}
         #ifdef SHADOWCSM{X}
-            for (int i = 0; i < SHADOWCSMNUM_CASCADES{X}; i++) 
+            for (int i = 0; i < SHADOWCSMNUM_CASCADES{X}; i++)
             {
                 #ifdef SHADOWCSM_RIGHTHANDED{X}
                     diff{X} = viewFrustumZ{X}[i] + vPositionFromCamera{X}.z;
@@ -335,7 +337,7 @@
         #else
             #ifdef SHADOWCSMDEBUG{X}
                 diffuseBase += info.diffuse * shadowDebug{X};
-            #else        
+            #else
                 diffuseBase += info.diffuse * shadow;
             #endif
             #ifdef SPECULARTERM

packages/dev/core/src/Shaders/ShadersInclude/pbrBlockAlbedoOpacity.fx

@@ -12,7 +12,7 @@ albedoOpacityOutParams albedoOpacityBlock(
     ,in vec2 albedoInfos
 #endif
     , in float baseWeight
-#ifdef BASEWEIGHT
+#ifdef BASE_WEIGHT
     , in vec4 baseWeightTexture
     , in vec2 vBaseWeightInfos
 #endif
@@ -75,7 +75,7 @@ albedoOpacityOutParams albedoOpacityBlock(
     //   applied in computeDiffuseLighting), but with the diffuse model *currently* used
     //   in Babylon.js, factoring it into the surfaceAlbedo is equivalent.
     surfaceAlbedo *= baseWeight;
-    #ifdef BASEWEIGHT
+    #ifdef BASE_WEIGHT
         surfaceAlbedo *= baseWeightTexture.r;
     #endif
 

packages/dev/core/src/Shaders/ShadersInclude/pbrDirectLightingFunctions.fx

@@ -20,7 +20,7 @@ struct lightingInfo
 // Simulate area (small) lights by increasing roughness
 float adjustRoughnessFromLightProperties(float roughness, float lightRadius, float lightDistance) {
     #if defined(USEPHYSICALLIGHTFALLOFF) || defined(USEGLTFLIGHTFALLOFF)
-        // At small angle this approximation works. 
+        // At small angle this approximation works.
         float lightRoughness = lightRadius / lightDistance;
         // Distribution can sum.
         float totalRoughness = saturate(lightRoughness + roughness);
@@ -41,7 +41,7 @@ vec3 computeHemisphericDiffuseLighting(preLightingInfo info, vec3 lightColor, ve
 #endif
 
 vec3 computeDiffuseLighting(preLightingInfo info, vec3 lightColor) {
-    float diffuseTerm = diffuseBRDF_Burley(info.NdotL, info.NdotV, info.VdotH, info.roughness);
+    float diffuseTerm = diffuseBRDF_Burley(info.NdotL, info.NdotV, info.VdotH, info.diffuseRoughness);
     return diffuseTerm * info.attenuation * info.NdotL * lightColor;
 }
 
@@ -64,7 +64,7 @@ vec3 computeProjectionTextureDiffuseLighting(sampler2D projectionLightSampler, m
         float trAdapt = step(0., info.NdotLUnclamped);
         vec3 transmittanceNdotL = mix(transmittance * wrapNdotL, vec3(wrapNdotL), trAdapt);
 
-        float diffuseTerm = diffuseBRDF_Burley(NdotL, info.NdotV, info.VdotH, info.roughness);
+        float diffuseTerm = diffuseBRDF_Burley(NdotL, info.NdotV, info.VdotH, info.diffuseRoughness);
         return diffuseTerm * transmittanceNdotL * info.attenuation * lightColor;
     }
 #endif

packages/dev/core/src/Shaders/ShadersInclude/pbrDirectLightingSetupFunctions.fx

@@ -16,7 +16,10 @@ struct preLightingInfo
     float NdotLUnclamped;
     float NdotL;
     float VdotH;
+
+     // TODO: the code would probably be leaner with material properties out of the structure.
     float roughness;
+    float diffuseRoughness;
 
     #ifdef IRIDESCENCE
         float iridescenceIntensity;
@@ -91,7 +94,7 @@ preLightingInfo computeHemisphericPreLightingInfo(vec4 lightData, vec3 V, vec3 N
 #if defined(AREALIGHTUSED) && defined(AREALIGHTSUPPORTED)
 #include<ltcHelperFunctions>
 
-preLightingInfo computeAreaPreLightingInfo(sampler2D ltc1, sampler2D ltc2, vec3 viewDirectionW, vec3 vNormal, vec3 vPosition, vec4 lightData, vec3 halfWidth, vec3 halfHeight, float roughness ) 
+preLightingInfo computeAreaPreLightingInfo(sampler2D ltc1, sampler2D ltc2, vec3 viewDirectionW, vec3 vNormal, vec3 vPosition, vec4 lightData, vec3 halfWidth, vec3 halfHeight, float roughness )
 {
 	preLightingInfo result;
     result.lightOffset = lightData.xyz - vPosition;
@@ -103,7 +106,7 @@ preLightingInfo computeAreaPreLightingInfo(sampler2D ltc1, sampler2D ltc2, vec3
 
 #ifdef SPECULARTERM
     result.areaLightFresnel = data.Fresnel;
-    result.areaLightSpecular = data.Specular;	
+    result.areaLightSpecular = data.Specular;
 #endif
 	result.areaLightDiffuse = data.Diffuse;
 	return result;