Created SurfaceData structure to centralize computation of frequently used shader temporary values

libraries/render-utils/src/DeferredBufferRead.slh

@@ -46,11 +46,14 @@ struct DeferredFragment {
     float depthVal;
 };
 
+<@if not GETFRESNEL0@>
+<@def GETFRESNEL0@>
 vec3 getFresnelF0(float metallic, vec3 metalF0) {
     // Enable continuous metallness value by lerping between dielectric
     // and metal fresnel F0 value based on the "metallic" parameter
     return mix(vec3(0.03), metalF0, metallic);
 }
+<@endif@>
 
 DeferredFragment unpackDeferredFragmentNoPosition(vec2 texcoord) {
     vec4 normalVal;

libraries/render-utils/src/DeferredGlobalLight.slh

@@ -65,10 +65,12 @@ vec3 albedo, vec3 fresnel, float metallic, float roughness
 
     <$prepareGlobalLight($supportScattering$)$>
 
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@> );
@@ -79,7 +81,7 @@ vec3 albedo, vec3 fresnel, float metallic, float roughness
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@> );
@@ -110,10 +112,12 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
     ) {
     <$prepareGlobalLight($supportScattering$)$>
 
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature 
 <@endif@>
@@ -123,7 +127,7 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
 
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@>
@@ -174,19 +178,21 @@ vec3 evalLightmappedColor(mat4 invViewMat, float shadowAttenuation, float obscur
 vec3 evalGlobalLightingAlphaBlended(mat4 invViewMat, float shadowAttenuation, float obscurance, vec3 position, vec3 normal, vec3 albedo, vec3 fresnel, float metallic, vec3 emissive, float roughness, float opacity) {
     <$prepareGlobalLight()$>
     
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     color += emissive * isEmissiveEnabled();
 
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance);
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance);
     color += ambientDiffuse;
     color += ambientSpecular / opacity;
 
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation);
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation);
     color += directionalDiffuse;
     color += directionalSpecular / opacity;
 
@@ -199,19 +205,21 @@ vec3 evalGlobalLightingAlphaBlendedWithHaze(
 {
     <$prepareGlobalLight()$>
     
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     color += emissive * isEmissiveEnabled();
 
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance);
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance);
     color += ambientDiffuse;
     color += ambientSpecular / opacity;
 
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation);
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation);
     color += directionalDiffuse;
     color += directionalSpecular / opacity;
 

libraries/render-utils/src/ForwardGlobalLight.slh

@@ -65,10 +65,12 @@ vec3 albedo, vec3 fresnel, float metallic, float roughness
 
     <$prepareGlobalLight($supportScattering$)$>
 
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@> );
@@ -79,7 +81,7 @@ vec3 albedo, vec3 fresnel, float metallic, float roughness
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@> );
@@ -109,10 +111,12 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
     ) {
     <$prepareGlobalLight($supportScattering$)$>
 
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature 
 <@endif@>
@@ -124,7 +128,7 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@>
@@ -173,19 +177,21 @@ vec3 evalLightmappedColor(mat4 invViewMat, float shadowAttenuation, float obscur
 vec3 evalGlobalLightingAlphaBlended(mat4 invViewMat, float shadowAttenuation, float obscurance, vec3 position, vec3 normal, vec3 albedo, vec3 fresnel, float metallic, vec3 emissive, float roughness, float opacity) {
     <$prepareGlobalLight()$>
     
+    SurfaceData surface = initSurfaceData(roughness, fragNormal, fragEyeDir);
+
     color += emissive * isEmissiveEnabled();
 
     // Ambient
     vec3 ambientDiffuse;
     vec3 ambientSpecular;
-    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, obscurance);
+    evalLightingAmbient(ambientDiffuse, ambientSpecular, lightAmbient, surface, metallic, fresnel, albedo, obscurance);
     color += ambientDiffuse;
     color += ambientSpecular / opacity;
 
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation);
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation);
     color += directionalDiffuse;
     color += directionalSpecular / opacity;
 

libraries/render-utils/src/LightAmbient.slh

@@ -22,8 +22,9 @@ vec4 evalSkyboxLight(vec3 direction, float lod) {
 
 <@func declareEvalAmbientSpecularIrradiance(supportAmbientSphere, supportAmbientMap, supportIfAmbientMapElseAmbientSphere)@>
 
-vec3  fresnelSchlickAmbient(vec3 fresnelColor, vec3 lightDir, vec3 halfDir, float gloss) {
+vec3  fresnelSchlickAmbient(vec3 fresnelColor, SurfaceData surface) {
-    float f = pow(1.0 - clamp(dot(lightDir, halfDir), 0.0, 1.0), 5.0);
+    float gloss = 1.0 - surface.roughness;
+    float f = pow(1.0 - surface.ldoth, 5.0);
     return fresnelColor + (max(vec3(gloss), fresnelColor) - fresnelColor) * f;
 //    return mix(fresnelColor, vec3(1.0), f);
 }
@@ -32,8 +33,8 @@ vec3  fresnelSchlickAmbient(vec3 fresnelColor, vec3 lightDir, vec3 halfDir, floa
 <$declareSkyboxMap()$>
 <@endif@>
 
-vec3 evalAmbientSpecularIrradiance(LightAmbient ambient, vec3 fragEyeDir, vec3 fragNormal, float roughness) {
+vec3 evalAmbientSpecularIrradiance(LightAmbient ambient, SurfaceData surface) {
-    vec3 lightDir = -reflect(fragEyeDir, fragNormal);
+    vec3 lightDir = -reflect(surface.eyeDir, surface.normal);
     vec3 specularLight;
     <@if supportIfAmbientMapElseAmbientSphere@>
         if (getLightHasAmbientMap(ambient))
@@ -41,8 +42,8 @@ vec3 evalAmbientSpecularIrradiance(LightAmbient ambient, vec3 fragEyeDir, vec3 f
             <@if supportAmbientMap@>
         {
             float levels = getLightAmbientMapNumMips(ambient);
-            float lod = min(((roughness)* levels), levels);
+            float lod = min(((surface.roughness)* levels), levels);
-            specularLight = evalSkyboxLight(lightDir, lod).xyz;
+            specularLight = evalSkyboxLight(surface.lightDir, lod).xyz;
             // We multiply specular by Pi to match specular / diffuse normalization in 
             // LightingModel.slh where diffuse and specular arent divided by Pi (when they should, rigourously
             // speaking, based on physical equations). The spherical harmonics evaluation, on
@@ -56,7 +57,7 @@ vec3 evalAmbientSpecularIrradiance(LightAmbient ambient, vec3 fragEyeDir, vec3 f
         <@endif@>
         <@if supportAmbientSphere@>
     {
-        specularLight = sphericalHarmonics_evalSphericalLight(getLightAmbientSphere(ambient), lightDir).xyz;
+        specularLight = sphericalHarmonics_evalSphericalLight(getLightAmbientSphere(ambient), surface.lightDir).xyz;
     }
     <@endif@>
 
@@ -74,21 +75,21 @@ float curvatureAO(in float k) {
 }
 <@endif@>
 
-void evalLightingAmbient(out vec3 diffuse, out vec3 specular, LightAmbient ambient, vec3 eyeDir, vec3 normal,
+void evalLightingAmbient(out vec3 diffuse, out vec3 specular, LightAmbient ambient, SurfaceData surface, 
-    float roughness, float metallic, vec3 fresnelF0, vec3 albedo, float obscurance
+                         float metallic, vec3 fresnelF0, vec3 albedo, float obscurance
 <@if supportScattering@>
     , float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
 <@endif@>
     ) {
 
     // Fresnel
-    vec3 ambientFresnel = fresnelSchlickAmbient(fresnelF0, eyeDir, normal, 1.0 - roughness);
+    vec3 ambientFresnel = fresnelSchlickAmbient(fresnelF0, surface);
 
     // Diffuse from ambient
-    diffuse = (1.0 - metallic) * (vec3(1.0) - ambientFresnel) * sphericalHarmonics_evalSphericalLight(getLightAmbientSphere(ambient), normal).xyz;
+    diffuse = (1.0 - metallic) * (vec3(1.0) - ambientFresnel) * sphericalHarmonics_evalSphericalLight(getLightAmbientSphere(ambient), surface.normal).xyz;
 
     // Specular highlight from ambient
-    specular = evalAmbientSpecularIrradiance(ambient, eyeDir, normal, roughness)  * ambientFresnel;
+    specular = evalAmbientSpecularIrradiance(ambient, surface)  * ambientFresnel;
 
 <@if supportScattering@>
     if (scattering * isScatteringEnabled() > 0.0) {

libraries/render-utils/src/LightDirectional.slh

@@ -12,7 +12,7 @@
 <@func declareLightingDirectional(supportScattering)@>
 
 void evalLightingDirectional(out vec3 diffuse, out vec3 specular, vec3 lightDir, vec3 lightIrradiance,
-    vec3 eyeDir, vec3 normal, float roughness,
+    SurfaceData surface,
     float metallic, vec3 fresnel, vec3 albedo, float shadow
 <@if supportScattering@>
     , float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
@@ -22,14 +22,17 @@ void evalLightingDirectional(out vec3 diffuse, out vec3 specular, vec3 lightDir,
     // Attenuation
     vec3 lightEnergy = shadow * lightIrradiance;
 
-    evalFragShading(diffuse, specular, normal, -lightDir, eyeDir, metallic, fresnel, roughness, albedo
+    updateSurfaceDataWithLight(surface, -lightDir);
+
+    evalFragShading(diffuse, specular, metallic, fresnel, surface, albedo
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@>
     );
 
-    diffuse *= lightEnergy * isDiffuseEnabled() * isDirectionalEnabled();
+    lightEnergy *= isDirectionalEnabled();
-    specular *= lightEnergy * isSpecularEnabled() * isDirectionalEnabled();
+    diffuse *= lightEnergy * isDiffuseEnabled();
+    specular *= lightEnergy * isSpecularEnabled();
 }
 
 <@endfunc@>

libraries/render-utils/src/LightPoint.slh

@@ -12,7 +12,7 @@
 <@func declareLightingPoint(supportScattering)@>
 
 void evalLightingPoint(out vec3 diffuse, out vec3 specular, Light light,
-    vec4 fragLightDirLen, vec3 fragEyeDir, vec3 normal, float roughness,
+    vec4 fragLightDirLen, SurfaceData surface,
     float metallic, vec3 fresnel, vec3 albedo, float shadow
 <@if supportScattering@>
     , float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
@@ -23,19 +23,22 @@ void evalLightingPoint(out vec3 diffuse, out vec3 specular, Light light,
     float fragLightDistance = fragLightDirLen.w;
     vec3 fragLightDir = fragLightDirLen.xyz;
 
+    updateSurfaceDataWithLight(surface, fragLightDir);
+
     // Eval attenuation
     float radialAttenuation = lightIrradiance_evalLightAttenuation(light.irradiance, fragLightDistance);
     vec3 lightEnergy = radialAttenuation * shadow * getLightIrradiance(light);
 
     // Eval shading
-    evalFragShading(diffuse, specular, normal, fragLightDir, fragEyeDir, metallic, fresnel, roughness, albedo
+    evalFragShading(diffuse, specular, metallic, fresnel, surface, albedo
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@>
     );
 
-    diffuse *= lightEnergy * isDiffuseEnabled() * isPointEnabled();
+    lightEnergy *= isPointEnabled();
-    specular *= lightEnergy * isSpecularEnabled() * isPointEnabled();
+    diffuse *= lightEnergy * isDiffuseEnabled();
+    specular *= lightEnergy * isSpecularEnabled();
 
     if (isShowLightContour() > 0.0) {
         // Show edge

libraries/render-utils/src/LightSpot.slh

@@ -12,7 +12,7 @@
 <@func declareLightingSpot(supportScattering)@>
 
 void evalLightingSpot(out vec3 diffuse, out vec3 specular, Light light,
-    vec4 fragLightDirLen, float cosSpotAngle, vec3 fragEyeDir, vec3 normal, float roughness,
+    vec4 fragLightDirLen, float cosSpotAngle, SurfaceData surface,
     float metallic, vec3 fresnel, vec3 albedo, float shadow
 <@if supportScattering@>
     , float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
@@ -23,6 +23,7 @@ void evalLightingSpot(out vec3 diffuse, out vec3 specular, Light light,
     float fragLightDistance = fragLightDirLen.w;
     vec3 fragLightDir = fragLightDirLen.xyz;
 
+    updateSurfaceDataWithLight(surface, fragLightDir);
 
     // Eval attenuation  
     float radialAttenuation = lightIrradiance_evalLightAttenuation(light.irradiance, fragLightDistance);
@@ -30,14 +31,15 @@ void evalLightingSpot(out vec3 diffuse, out vec3 specular, Light light,
     vec3 lightEnergy = angularAttenuation * radialAttenuation * shadow *getLightIrradiance(light);
 
     // Eval shading
-    evalFragShading(diffuse, specular, normal, fragLightDir, fragEyeDir, metallic, fresnel, roughness, albedo
+    evalFragShading(diffuse, specular, metallic, fresnel, surface, albedo
 <@if supportScattering@>
     ,scattering, midNormalCurvature, lowNormalCurvature
 <@endif@>
     );
     
-    diffuse *= lightEnergy * isDiffuseEnabled() * isSpotEnabled();
+    lightEnergy *= isSpotEnabled();
-    specular *= lightEnergy * isSpecularEnabled() * isSpotEnabled();
+    diffuse *= lightEnergy * isDiffuseEnabled();
+    specular *= lightEnergy * isSpecularEnabled();
 
     if (isShowLightContour() > 0.0) {
         // Show edges

libraries/render-utils/src/LightingModel.slh

@@ -77,6 +77,30 @@ float isWireframeEnabled() {
 <@endfunc@>
 <$declareLightingModel()$>
 
+struct SurfaceData {
+    vec3 normal;
+    vec3 eyeDir;
+    vec3 lightDir;
+    vec3 halfDir;
+    float roughness;
+    float roughness2;
+    float roughness4;
+    float ndotv;
+    float ndotl;
+    float ndoth;
+    float ldoth;
+    float smithInvG1NdotV;
+};
+
+<@if not GETFRESNEL0@>
+<@def GETFRESNEL0@>
+vec3 getFresnelF0(float metallic, vec3 metalF0) {
+    // Enable continuous metallness value by lerping between dielectric
+    // and metal fresnel F0 value based on the "metallic" parameter
+    return mix(vec3(0.03), metalF0, metallic);
+}
+<@endif@>
+
 <@func declareBeckmannSpecular()@>
 
 uniform sampler2D scatteringSpecularBeckmann;
@@ -85,17 +109,13 @@ float fetchSpecularBeckmann(float ndoth, float roughness) {
     return pow(2.0 * texture(scatteringSpecularBeckmann, vec2(ndoth, roughness)).r, 10.0);
 }
 
-vec2 skinSpecular(vec3 N, vec3 L, vec3 V, float roughness, float intensity) {
+vec2 skinSpecular(SurfaceData surface, float intensity) {
     vec2 result = vec2(0.0, 1.0);
-    float ndotl = dot(N, L);
+    if (surface.ndotl > 0.0) {
-    if (ndotl > 0.0) {
+        float PH = fetchSpecularBeckmann(surface.ndoth, surface.roughness);
-        vec3 h = L + V;
+        float F = fresnelSchlickScalar(0.028, surface);
-        vec3 H = normalize(h);
+        float frSpec = max(PH * F / dot(surface.halfDir, surface.halfDir), 0.0);
-        float ndoth = dot(N, H);
+        result.x = surface.ndotl * intensity * frSpec;
-        float PH = fetchSpecularBeckmann(ndoth, roughness);
-        float F = fresnelSchlickScalar(0.028, H, V);
-        float frSpec = max(PH * F / dot(h, h), 0.0);
-        result.x = ndotl * intensity * frSpec;
         result.y -= F;
     }
 
@@ -105,83 +125,105 @@ vec2 skinSpecular(vec3 N, vec3 L, vec3 V, float roughness, float intensity) {
 
 <@func declareEvalPBRShading()@>
 
-vec3 fresnelSchlickColor(vec3 fresnelColor, vec3 lightDir, vec3 halfDir) {
+float evalSmithInvG1(float roughness4, float ndotd) {
-    float base = 1.0 - clamp(dot(lightDir, halfDir), 0.0, 1.0);
+    return ndotd + sqrt(roughness4+ndotd*ndotd*(1.0-roughness4));
+}
+
+SurfaceData initSurfaceData(float roughness, vec3 normal, vec3 eyeDir) {
+    SurfaceData surface;
+    surface.eyeDir = eyeDir;
+    surface.normal = normal;
+    surface.lightDir = vec3(0,0,0);
+    surface.halfDir = vec3(0,0,0);
+    surface.roughness = mix(0.001, 1.0, roughness);
+    surface.roughness2 = surface.roughness * surface.roughness;
+    surface.roughness4 = surface.roughness2 * surface.roughness2;
+    surface.ndotv = clamp(dot(normal, eyeDir), 0.0, 1.0);
+    surface.ndoth = 0.0;
+    surface.ndotl = 0.0;
+    surface.ldoth = 0.0;
+    surface.smithInvG1NdotV = evalSmithInvG1(surface.roughness4, surface.ndotv);
+    return surface;
+}
+
+void updateSurfaceDataWithLight(inout SurfaceData surface, vec3 lightDir) {
+    surface.lightDir = lightDir;
+    surface.halfDir = normalize(surface.eyeDir + lightDir);
+    vec3 dots;
+    dots.x = dot(surface.normal, surface.halfDir);
+    dots.y = dot(surface.normal, surface.lightDir);
+    dots.z = dot(surface.halfDir, surface.lightDir);
+    dots = clamp(dots, vec3(0), vec3(1));
+    surface.ndoth = dots.x;
+    surface.ndotl = dots.y;
+    surface.ldoth = dots.z;
+}
+
+vec3 fresnelSchlickColor(vec3 fresnelColor, SurfaceData surface) {
+    float base = 1.0 - surface.ldoth;
     //float exponential = pow(base, 5.0);
     float base2 = base * base;
     float exponential = base * base2 * base2;
     return vec3(exponential) + fresnelColor * (1.0 - exponential);
 }
 
-float fresnelSchlickScalar(float fresnelScalar, vec3 lightDir, vec3 halfDir) {
+float fresnelSchlickScalar(float fresnelScalar, SurfaceData surface) {
-    float base = 1.0 - clamp(dot(lightDir, halfDir), 0.0, 1.0);
+    float base = 1.0 - surface.ldoth;
     //float exponential = pow(base, 5.0);
     float base2 = base * base;
     float exponential = base * base2 * base2;
     return (exponential) + fresnelScalar * (1.0 - exponential);
 }
 
-float specularDistribution(float roughness, vec3 normal, vec3 halfDir, vec3 eyeDir, float ndotl) {
+float specularDistribution(SurfaceData surface) {
     // See https://www.khronos.org/assets/uploads/developers/library/2017-web3d/glTF-2.0-Launch_Jun17.pdf
     // for details of equations, especially page 20
-    float ndoth = dot(halfDir, normal);
+    float denom = (surface.ndoth*surface.ndoth * (surface.roughness2 - 1.0) + 1.0);
-    float ndotv = dot(eyeDir, normal);
-    vec3 nd = clamp(vec3(ndoth, ndotv, ndotl), vec3(0.0), vec3(1.0));
-    vec3 nd2 = nd * nd;
-    float roughness2 = mix(0.001, 1.0, roughness);
-    roughness2 *= roughness2; // pow 2
-    float roughness4 = roughness2;
-    roughness4 *= roughness4; // pow 4
-    float denom = (nd2.x * (roughness2 - 1.0) + 1.0);
     denom *= denom;
     // Add geometric factors G1(n,l) and G1(n,v)
-    float oneMinusRoughness4 = 1.0-roughness4;
+    float smithInvG1NdotL = evalSmithInvG1(surface.roughness4, surface.ndotl);
-    vec2 invG = nd.yz + sqrt(vec2(roughness4)+nd2.yz*oneMinusRoughness4);
+    denom *= surface.smithInvG1NdotV * smithInvG1NdotL;
-    denom *= invG.x * invG.y;
     // Don't divide by PI as diffuse isn't either. The real PBR formula normalizes
     // by PI on both but if we decide to not do it, it is just as if we
     // multiplied all our lights by PI
     //denom *= 3.1415926;
-    float power = roughness4 / denom;
+    float power = surface.roughness4 / denom;
     return power;
 }
 
 // Frag Shading returns the diffuse amount as W and the specular rgb as xyz
-vec4 evalPBRShading(vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir, float metallic, vec3 fresnel, float roughness) {
+vec4 evalPBRShading(float metallic, vec3 fresnel, SurfaceData surface) {
     // Incident angle attenuation
-    float angleAttenuation = clamp(dot(fragNormal, fragLightDir), 0.0, 1.0);
+    float angleAttenuation = surface.ndotl;
 
     // Specular Lighting
-    vec3 halfDir = normalize(fragEyeDir + fragLightDir);
+    vec3 fresnelColor = fresnelSchlickColor(fresnel, surface);
-    vec3 fresnelColor = fresnelSchlickColor(fresnel, fragLightDir, halfDir);
+    float power = specularDistribution(surface);
-    float power = specularDistribution(roughness, fragNormal, halfDir, fragEyeDir, angleAttenuation);
     vec3 specular = fresnelColor * power * angleAttenuation;
 
     return vec4(specular, (1.0 - metallic) * angleAttenuation * (1.0 - fresnelColor.x));
 }
 
 // Frag Shading returns the diffuse amount as W and the specular rgb as xyz
-vec4 evalPBRShadingDielectric(vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir, float roughness, float fresnel) {
+vec4 evalPBRShadingDielectric(SurfaceData surface, float fresnel) {
     // Incident angle attenuation
-    float angleAttenuation = clamp(dot(fragNormal, fragLightDir), 0.0, 1.0);
+    float angleAttenuation = surface.ndotl;
 
     // Specular Lighting
-    vec3 halfDir = normalize(fragEyeDir + fragLightDir);
+    float fresnelScalar = fresnelSchlickScalar(fresnel, surface);
-    float fresnelScalar = fresnelSchlickScalar(fresnel, fragLightDir, halfDir);
+    float power = specularDistribution(surface);
-    float power = specularDistribution(roughness, fragNormal, halfDir, fragEyeDir, angleAttenuation);
     vec3 specular = vec3(fresnelScalar) * power * angleAttenuation;
 
     return vec4(specular,  angleAttenuation * (1.0 - fresnelScalar));
 }
 
-vec4 evalPBRShadingMetallic(vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir, float roughness, vec3 fresnel) {
+vec4 evalPBRShadingMetallic(SurfaceData surface, vec3 fresnel) {
     // Incident angle attenuation
-    float angleAttenuation = clamp(dot(fragNormal, fragLightDir), 0.0, 1.0);
+    float angleAttenuation = surface.ndotl;
 
     // Specular Lighting
-    vec3 halfDir = normalize(fragEyeDir + fragLightDir);
+    vec3 fresnelColor = fresnelSchlickColor(fresnel, surface);
-    vec3 fresnelColor = fresnelSchlickColor(fresnel, fragLightDir, halfDir);
+    float power = specularDistribution(surface);
-    float power = specularDistribution(roughness, fragNormal, halfDir, fragEyeDir, angleAttenuation);
     vec3 specular = fresnelColor * power * angleAttenuation;
 
     return vec4(specular, 0.f);
@@ -193,15 +235,9 @@ vec4 evalPBRShadingMetallic(vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir,
 
 <$declareEvalPBRShading()$>
 
-// Return xyz the specular/reflection component and w the diffuse component
-//vec4 evalFragShading(vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir, float metallic, vec3 fresnel, float roughness) {
-//    return evalPBRShading(fragNormal, fragLightDir, fragEyeDir, metallic, fresnel, roughness);
-//}
-
 void evalFragShading(out vec3 diffuse, out vec3 specular,
-    vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir,
+    float metallic, vec3 fresnel, SurfaceData surface, vec3 albedo) {
-    float metallic, vec3 fresnel, float roughness, vec3 albedo) {
+    vec4 shading = evalPBRShading(metallic, fresnel, surface);
-    vec4 shading = evalPBRShading(fragNormal, fragLightDir, fragEyeDir, metallic, fresnel, roughness);
     diffuse = vec3(shading.w);
     if (isAlbedoEnabled() > 0.0) {
         diffuse *= albedo;
@@ -215,22 +251,19 @@ void evalFragShading(out vec3 diffuse, out vec3 specular,
 
 
 void evalFragShading(out vec3 diffuse, out vec3 specular,
-    vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir,
+    float metallic, vec3 fresnel, SurfaceData surface, vec3 albedo,
-    float metallic, vec3 fresnel, float roughness, vec3 albedo,
     float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature) {
     if (scattering * isScatteringEnabled() > 0.0) {
-        vec3 brdf = evalSkinBRDF(fragLightDir, fragNormal, midNormalCurvature.xyz, lowNormalCurvature.xyz, lowNormalCurvature.w);
+        vec3 brdf = evalSkinBRDF(surface.lightDir, surface.normal, midNormalCurvature.xyz, lowNormalCurvature.xyz, lowNormalCurvature.w);
-        float NdotL = clamp(dot(fragNormal, fragLightDir), 0.0, 1.0);
+        diffuse = mix(vec3(surface.ndotl), brdf, scattering);
-        diffuse = mix(vec3(NdotL), brdf, scattering);
 
         // Specular Lighting
-        vec3 halfDir = normalize(fragEyeDir + fragLightDir);
+        vec2 specularBrdf = skinSpecular(surface, 1.0);
-        vec2 specularBrdf = skinSpecular(fragNormal, fragLightDir, fragEyeDir, roughness, 1.0);
         
         diffuse *= specularBrdf.y;
         specular = vec3(specularBrdf.x);
     } else {
-        vec4 shading = evalPBRShading(fragNormal, fragLightDir, fragEyeDir, metallic, fresnel, roughness);
+        vec4 shading = evalPBRShading(metallic, fresnel, surface);
         diffuse = vec3(shading.w);
         specular = shading.xyz;
     }
@@ -239,17 +272,15 @@ void evalFragShading(out vec3 diffuse, out vec3 specular,
 
 
 void evalFragShadingScattering(out vec3 diffuse, out vec3 specular,
-    vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir,
+    float metallic, vec3 fresnel, SurfaceData surface, vec3 albedo
-    float metallic, vec3 fresnel, float roughness, vec3 albedo
     ,float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
 ) {
-    vec3 brdf = evalSkinBRDF(fragLightDir, fragNormal, midNormalCurvature.xyz, lowNormalCurvature.xyz, lowNormalCurvature.w);
+    vec3 brdf = evalSkinBRDF(surface.lightDir, surface.normal, midNormalCurvature.xyz, lowNormalCurvature.xyz, lowNormalCurvature.w);
-    float NdotL = clamp(dot(fragNormal, fragLightDir), 0.0, 1.0);
+    float NdotL = surface.ndotl;
     diffuse = mix(vec3(NdotL), brdf, scattering);
 
     // Specular Lighting
-    vec3 halfDir = normalize(fragEyeDir + fragLightDir);
+    vec2 specularBrdf = skinSpecular(surface, 1.0);
-    vec2 specularBrdf = skinSpecular(fragNormal, fragLightDir, fragEyeDir, roughness, 1.0);
         
     diffuse *= specularBrdf.y;
     specular = vec3(specularBrdf.x);
@@ -257,10 +288,9 @@ void evalFragShadingScattering(out vec3 diffuse, out vec3 specular,
 }
 
 void evalFragShadingGloss(out vec3 diffuse, out vec3 specular,
-    vec3 fragNormal, vec3 fragLightDir, vec3 fragEyeDir,
+    float metallic, vec3 fresnel, SurfaceData surface, vec3 albedo
-    float metallic, vec3 fresnel, float gloss, vec3 albedo
 ) {
-    vec4 shading = evalPBRShading(fragNormal, fragLightDir, fragEyeDir, metallic, fresnel, gloss);
+    vec4 shading = evalPBRShading(metallic, fresnel, surface);
     diffuse = vec3(shading.w);
     diffuse *= mix(vec3(1.0), albedo, isAlbedoEnabled());
     specular = shading.xyz;

libraries/render-utils/src/SubsurfaceScattering.slh

@@ -63,38 +63,6 @@ vec3 scatter(float r) {
 <@endfunc@>
 
 
-<@func declareSkinSpecularLighting()@>
-
-uniform sampler2D scatteringSpecularBeckmann;
-
-float fetchSpecularBeckmann(float ndoth, float roughness) {
-    return pow( 2.0 * texture(scatteringSpecularBeckmann, vec2(ndoth, roughness)).r, 10.0);
-}
-
-float fresnelReflectance(vec3 H, vec3 V, float Fo) {
-    float base = 1.0 - dot(V, H);
-    float exponential = pow(base, 5.0);
-    return exponential + Fo * (1.0 - exponential);
-}
-
-float skinSpecular(vec3 N, vec3 L, vec3 V, float roughness, float intensity) {
-    float result = 0.0;
-    float ndotl = dot(N, L);
-    if (ndotl > 0.0) {
-        vec3 h = L + V;
-        vec3 H = normalize(h);
-        float ndoth = dot(N, H);
-        float PH = fetchSpecularBeckmann(ndoth, roughness);
-        float F = fresnelReflectance(H, V, 0.028);
-        float frSpec = max(PH * F / dot(h, h), 0.0);
-        result = ndotl * intensity * frSpec;
-    }
-
-    return result;
-}
-
-<@endfunc@>
-
 <@func declareSubsurfaceScatteringIntegrate(NumIntegrationSteps)@>
 
 

libraries/render-utils/src/local_lights_shading.slf

@@ -84,9 +84,8 @@ void main(void) {
     // Frag to eye vec
     vec4 fragEyeVector = invViewMat * vec4(-frag.position.xyz, 0.0);
     vec3 fragEyeDir = normalize(fragEyeVector.xyz);
-
+    
-    // Compute the rougness into gloss2 once:
+    SurfaceData surface = initSurfaceData(frag.roughness, frag.normal, fragEyeDir);
-    float fragGloss2 = pow(frag.roughness + 0.001, 4.0);
     bool withScattering = (frag.scattering * isScatteringEnabled() > 0.0);
 
     int numLightTouching = 0;
@@ -119,16 +118,18 @@ void main(void) {
         float fragLightDistance = fragLightDirLen.w;
         vec3 fragLightDir = fragLightDirLen.xyz;
 
+        updateSurfaceDataWithLight(surface, fragLightDir);
+
         // Eval attenuation
         float radialAttenuation = lightIrradiance_evalLightAttenuation(light.irradiance, fragLightDistance);
         vec3 lightEnergy = radialAttenuation * getLightIrradiance(light);
 
         // Eval shading
         if (withScattering) {
-            evalFragShadingScattering(diffuse, specular, frag.normal, fragLightDir, fragEyeDir, frag.metallic, frag.fresnel, frag.roughness, frag.albedo
+            evalFragShadingScattering(diffuse, specular, frag.metallic, frag.fresnel, surface, frag.albedo
                 ,frag.scattering, midNormalCurvature, lowNormalCurvature );
         } else {
-           evalFragShadingGloss(diffuse, specular, frag.normal, fragLightDir, fragEyeDir, frag.metallic, frag.fresnel, fragGloss2, frag.albedo);
+           evalFragShadingGloss(diffuse, specular, frag.metallic, frag.fresnel, surface, frag.albedo);
         }
 
         diffuse *= lightEnergy * isDiffuseEnabled();
@@ -173,6 +174,8 @@ void main(void) {
         float fragLightDistance = fragLightDirLen.w;
         vec3 fragLightDir = fragLightDirLen.xyz;
 
+        updateSurfaceDataWithLight(surface, fragLightDir);
+
         // Eval attenuation
         float radialAttenuation = lightIrradiance_evalLightAttenuation(light.irradiance, fragLightDistance);
         float angularAttenuation = lightIrradiance_evalLightSpotAttenuation(light.irradiance, cosSpotAngle);
@@ -180,10 +183,10 @@ void main(void) {
 
         // Eval shading
         if (withScattering) {
-            evalFragShadingScattering(diffuse, specular, frag.normal, fragLightDir, fragEyeDir, frag.metallic, frag.fresnel, frag.roughness, frag.albedo
+            evalFragShadingScattering(diffuse, specular, frag.metallic, frag.fresnel, surface, frag.albedo
                 ,frag.scattering, midNormalCurvature, lowNormalCurvature );
         } else {
-           evalFragShadingGloss(diffuse, specular, frag.normal, fragLightDir, fragEyeDir, frag.metallic, frag.fresnel, fragGloss2, frag.albedo);
+           evalFragShadingGloss(diffuse, specular, frag.metallic, frag.fresnel, surface, frag.albedo);
         }
 
         diffuse *= lightEnergy * isDiffuseEnabled();

libraries/render-utils/src/model_translucent.slf

@@ -50,13 +50,7 @@ void main(void) {
     <$evalMaterialRoughness(roughnessTex, roughness, matKey, roughness)$>;
 
     float metallic = getMaterialMetallic(mat);
-    vec3 fresnel = vec3(0.03); // Default Di-electric fresnel value
+    vec3 fresnel = getFresnelF0(metallic, albedo);
-    if (metallic <= 0.5) {
-        metallic = 0.0;
-    } else {
-        fresnel = albedo;
-        metallic = 1.0;
-    }
 
     vec3 emissive = getMaterialEmissive(mat);
     <$evalMaterialEmissive(emissiveTex, emissive, matKey, emissive)$>;

libraries/render-utils/src/model_translucent_fade.slf

@@ -60,13 +60,7 @@ void main(void) {
     <$evalMaterialRoughness(roughnessTex, roughness, matKey, roughness)$>;
 
     float metallic = getMaterialMetallic(mat);
-    vec3 fresnel = vec3(0.03); // Default Di-electric fresnel value
+    vec3 fresnel = getFresnelF0(metallic, albedo);
-    if (metallic <= 0.5) {
-        metallic = 0.0;
-    } else {
-        fresnel = albedo;
-        metallic = 1.0;
-    }
 
     vec3 emissive = getMaterialEmissive(mat);
     <$evalMaterialEmissive(emissiveTex, emissive, matKey, emissive)$>;

libraries/render-utils/src/overlay3D.slf

@@ -40,12 +40,14 @@ vec4 evalGlobalColor(float shadowAttenuation, vec3 position, vec3 normal, vec3 a
     vec3 fragEyeDir;
     <$transformEyeToWorldDir(cam, fragEyeVectorView, fragEyeDir)$>
 
+    SurfaceData surface = initSurfaceData(roughness, normal, fragEyeDir);
+
     vec3 color = opacity * albedo * getLightColor(light) * getLightAmbientIntensity(ambient);
 
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation);
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation);
     color += directionalDiffuse * isDiffuseEnabled() * isDirectionalEnabled();
     color += directionalSpecular * isSpecularEnabled() * isDirectionalEnabled();
 

libraries/render-utils/src/overlay3D_translucent.slf

@@ -40,12 +40,14 @@ vec4 evalGlobalColor(float shadowAttenuation, vec3 position, vec3 normal, vec3 a
     vec3 fragEyeDir;
     <$transformEyeToWorldDir(cam, fragEyeVectorView, fragEyeDir)$>
 
+    SurfaceData surface = initSurfaceData(roughness, normal, fragEyeDir);
+
     vec3 color = opacity * albedo * getLightColor(light) * getLightAmbientIntensity(ambient);
 
     // Directional
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
-    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation);
+    evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, surface, metallic, fresnel, albedo, shadowAttenuation);
     color += directionalDiffuse;
     color += directionalSpecular / opacity;