HDRenderLoop: Continue to add misc function (intersection, aniso support)

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/LightDefinition.cs.hlsl

 // PackingRules = Exact
 struct PunctualLightData
 {
-    float3 positionWS;
-    float invSqrAttenuationRadius;
-    float3 color;
-    float useDistanceAttenuation;
-    float3 forward;
-    float diffuseScale;
-    float3 up;
-    float specularScale;
-    float3 right;
-    float shadowDimmer;
-    float angleScale;
-    float angleOffset;
-    float2 unused2;
+	float3 positionWS;
+	float invSqrAttenuationRadius;
+	float3 color;
+	float useDistanceAttenuation;
+	float3 forward;
+	float diffuseScale;
+	float3 up;
+	float specularScale;
+	float3 right;
+	float shadowDimmer;
+	float angleScale;
+	float angleOffset;
+	float2 unused2;
 };
 
 // Generated from UnityEngine.ScriptableRenderLoop.AreaLightData
-    float3 positionWS;
+	float3 positionWS;
 };
 
 // Generated from UnityEngine.ScriptableRenderLoop.EnvLightData
-    float3 positionWS;
+	float3 positionWS;
 };
 
 // Generated from UnityEngine.ScriptableRenderLoop.PlanarLightData
-    float3 positionWS;
+	float3 positionWS;
 };
 
 //
 {
-    return value.positionWS;
+	return value.positionWS;
-    return value.invSqrAttenuationRadius;
+	return value.invSqrAttenuationRadius;
-    return value.color;
+	return value.color;
-    return value.useDistanceAttenuation;
+	return value.useDistanceAttenuation;
-    return value.forward;
+	return value.forward;
-    return value.diffuseScale;
+	return value.diffuseScale;
-    return value.up;
+	return value.up;
-    return value.specularScale;
+	return value.specularScale;
-    return value.right;
+	return value.right;
-    return value.shadowDimmer;
+	return value.shadowDimmer;
-    return value.angleScale;
+	return value.angleScale;
-    return value.angleOffset;
+	return value.angleOffset;
-    return value.unused2;
+	return value.unused2;
 }
 
 //
 {
-    return value.positionWS;
+	return value.positionWS;
 }
 
 //
 {
-    return value.positionWS;
+	return value.positionWS;
 }
 
 //
 {
-    return value.positionWS;
+	return value.positionWS;
+
+

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/LightingForward.hlsl

     }
     */
 
-    for (int i = 0; i < _EnvLightCount; ++i)
+    for (int j = 0; j < _EnvLightCount; ++j)
-        EvaluateBSDF_Env(V, positionWS, prelightData, _EnvLightList[i], bsdfData, UNITY_PASS_ENV(_ReflCubeTextures), localDiffuseLighting, localSpecularLighting);
+        EvaluateBSDF_Env(V, positionWS, prelightData, _EnvLightList[j], bsdfData, UNITY_PASS_ENV(_ReflCubeTextures), localDiffuseLighting, localSpecularLighting);
         diffuseLighting += localDiffuseLighting;
         specularLighting += localSpecularLighting;
     }

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/LitTemplate.hlsl

     surfaceData.metalic *= _Metalic;
 
 
-    surfaceData.tangentWS = float3(1.0, 0.0, 0.0);
+    surfaceData.tangentWS = input.tangentToWorld[0].xyz;
     surfaceData.anisotropy = 0;
     surfaceData.specular = 0.04;
 

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/BuiltinData.cs.hlsl

 // PackingRules = Exact
 struct BuiltinData
 {
-    float opacity;
-    float3 bakeDiffuseLighting;
-    float3 emissiveColor;
-    float emissiveIntensity;
-    float2 velocity;
-    float2 distortion;
-    float distortionBlur;
+	float opacity;
+	float3 bakeDiffuseLighting;
+	float3 emissiveColor;
+	float emissiveIntensity;
+	float2 velocity;
+	float2 distortion;
+	float distortionBlur;
+
+

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit.cs

             public Vector3 bitangentWS;
             public float roughnessT;
             public float roughnessB;
+            public float anisotropy;
 
             // fold into fresnel0
 

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit.cs.hlsl

 #define DEBUGVIEW_LIT_BSDFDATA_BITANGENT_WS (1038)
 #define DEBUGVIEW_LIT_BSDFDATA_ROUGHNESS_T (1039)
 #define DEBUGVIEW_LIT_BSDFDATA_ROUGHNESS_B (1040)
-#define DEBUGVIEW_LIT_BSDFDATA_SUB_SURFACE_RADIUS (1041)
-#define DEBUGVIEW_LIT_BSDFDATA_THICKNESS (1042)
-#define DEBUGVIEW_LIT_BSDFDATA_SUB_SURFACE_PROFILE (1043)
-#define DEBUGVIEW_LIT_BSDFDATA_COAT_NORMAL_WS (1044)
-#define DEBUGVIEW_LIT_BSDFDATA_COAT_ROUGHNESS (1045)
+#define DEBUGVIEW_LIT_BSDFDATA_ANISOTROPY (1041)
+#define DEBUGVIEW_LIT_BSDFDATA_SUB_SURFACE_RADIUS (1042)
+#define DEBUGVIEW_LIT_BSDFDATA_THICKNESS (1043)
+#define DEBUGVIEW_LIT_BSDFDATA_SUB_SURFACE_PROFILE (1044)
+#define DEBUGVIEW_LIT_BSDFDATA_COAT_NORMAL_WS (1045)
+#define DEBUGVIEW_LIT_BSDFDATA_COAT_ROUGHNESS (1046)
-    float3 baseColor;
-    float specularOcclusion;
-    float3 normalWS;
-    float perceptualSmoothness;
-    int materialId;
-    float ambientOcclusion;
-    float3 tangentWS;
-    float anisotropy;
-    float metalic;
-    float specular;
-    float subSurfaceRadius;
-    float thickness;
-    int subSurfaceProfile;
-    float3 coatNormalWS;
-    float coatPerceptualSmoothness;
-    float3 specularColor;
+	float3 baseColor;
+	float specularOcclusion;
+	float3 normalWS;
+	float perceptualSmoothness;
+	int materialId;
+	float ambientOcclusion;
+	float3 tangentWS;
+	float anisotropy;
+	float metalic;
+	float specular;
+	float subSurfaceRadius;
+	float thickness;
+	int subSurfaceProfile;
+	float3 coatNormalWS;
+	float coatPerceptualSmoothness;
+	float3 specularColor;
 };
 
 // Generated from UnityEngine.ScriptableRenderLoop.Lit.BSDFData
-    float3 diffuseColor;
-    float3 fresnel0;
-    float specularOcclusion;
-    float3 normalWS;
-    float perceptualRoughness;
-    float roughness;
-    float materialId;
-    float3 tangentWS;
-    float3 bitangentWS;
-    float roughnessT;
-    float roughnessB;
-    float subSurfaceRadius;
-    float thickness;
-    int subSurfaceProfile;
-    float3 coatNormalWS;
-    float coatRoughness;
+	float3 diffuseColor;
+	float3 fresnel0;
+	float specularOcclusion;
+	float3 normalWS;
+	float perceptualRoughness;
+	float roughness;
+	float materialId;
+	float3 tangentWS;
+	float3 bitangentWS;
+	float roughnessT;
+	float roughnessB;
+	float anisotropy;
+	float subSurfaceRadius;
+	float thickness;
+	int subSurfaceProfile;
+	float3 coatNormalWS;
+	float coatRoughness;
+
+

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit.hlsl

         bsdfData.fresnel0 = lerp(float3(surfaceData.specular, surfaceData.specular, surfaceData.specular), surfaceData.baseColor, surfaceData.metalic);
 
         bsdfData.tangentWS = surfaceData.tangentWS;
-        bsdfData.bitangentWS = cross(surfaceData.normalWS, surfaceData.tangentWS);
+        bsdfData.bitangentWS = cross(surfaceData.normalWS, surfaceData.tangentWS);        
+        bsdfData.anisotropy = surfaceData.anisotropy;
 
         bsdfData.materialId = surfaceData.anisotropy > 0 ? MATERIALID_LIT_ANISO : bsdfData.materialId;
     }
         bsdfData.tangentWS = UnpackNormalOctEncode(float2(inGBuffer2.rg * 2.0 - 1.0));
         bsdfData.bitangentWS = cross(bsdfData.normalWS, bsdfData.tangentWS);
         ConvertAnisotropyToRoughness(bsdfData.roughness, anisotropy, bsdfData.roughnessT, bsdfData.roughnessB);
+        bsdfData.anisotropy = anisotropy;
 
         bsdfData.materialId = anisotropy > 0 ? MATERIALID_LIT_ANISO : bsdfData.materialId;
     }
         case DEBUGVIEW_LIT_BSDFDATA_ROUGHNESS_B:
             result = bsdfData.roughnessB.xxx;
             break;
+        case DEBUGVIEW_LIT_BSDFDATA_ANISOTROPY:
+            result = bsdfData.anisotropy.xxx;
+            break;
         case DEBUGVIEW_LIT_BSDFDATA_SUB_SURFACE_RADIUS:
             result = bsdfData.subSurfaceRadius.xxx;
             break;
 struct PreLightData
 {
     float NdotV;
+    float3 R;
+    float ggxLambdaV;
-
-    float ggxLambdaV;
+    
+    float3 anisoNormalWS;
+    float3 anisoR; // TODO: check if this is needed, I don't think we use R anymore for other thing than imagebased lighting
-    // image based lighting
-    float3 R;
+    // image based lighting    
     float3 specularDFG;
     float diffuseDFG;
 
     preLightData.NdotV = GetNdotV(bsdfData.normalWS, V);
 #endif
 
+    preLightData.R = reflect(-V, bsdfData.normalWS);
     preLightData.ggxLambdaV = GetSmithJointGGXLambdaV(preLightData.NdotV, bsdfData.roughness);
 
     // Check if we precompute anisotropy too (should not be necessary as if the variables are not used they will be optimize out, but may avoid
         preLightData.BdotV = dot(bsdfData.bitangentWS, bsdfData.normalWS);
+        preLightData.anisoGGXLambdaV = GetSmithJointGGXAnisoLambdaV(preLightData.TdotV, preLightData.BdotV, preLightData.NdotV, bsdfData.roughnessT, bsdfData.roughnessB);
+        preLightData.anisoNormalWS = GetAnisotropicModifiedNormal(bsdfData.normalWS, bsdfData.tangentWS, V, bsdfData.anisotropy);
-        preLightData.anisoGGXLambdaV = GetSmithJointGGXAnisoLambdaV(preLightData.TdotV, preLightData.BdotV, preLightData.NdotV, bsdfData.roughnessT, bsdfData.roughnessB);
+        // We need to take into account the modified normal for faking anisotropic here.
+        float anisoNdotV = GetNdotV(preLightData.anisoNormalWS, V); // TODO: is it necessary here to use the GetNDotV function
+        preLightData.anisoR = reflect(-V, preLightData.anisoNormalWS); // TODO: check if this is needed, I don't think we use R anymore for other thing than imagebased lighting
+        GetPreIntegratedDFG(anisoNdotV, bsdfData.roughness, bsdfData.fresnel0, preLightData.specularDFG, preLightData.diffuseDFG);
+    }
+    else
+    {
+        GetPreIntegratedDFG(preLightData.NdotV, bsdfData.roughness, bsdfData.fresnel0, preLightData.specularDFG, preLightData.diffuseDFG);
-
-    preLightData.R = reflect(-V, bsdfData.normalWS);
-
-    GetPreIntegratedDFG(preLightData.NdotV, bsdfData.roughness, bsdfData.fresnel0, preLightData.specularDFG, preLightData.diffuseDFG);
 
     // #if SHADERPASS == SHADERPASS_GBUFFER
     // preLightData.ambientOcclusion = _AmbientOcclusion.Load(uint3(coord.unPositionSS, 0)).x;
     }
 }
 
+// TODO: We need to change this hard limit!
+#define UNITY_SPECCUBE_LOD_STEPS (6)
+
+float perceptualRoughnessToMipmapLevel(float perceptualRoughness)
+{
+    // TODO: Clean a bit this code
+    // CAUTION: remap from Morten may work only with offline convolution, see impact with runtime convolution!
+
+    // For now disabled
+#if 0
+    float m = PerceptualRoughnessToRoughness(perceptualRoughness); // m is the real roughness parameter
+    const float fEps = 1.192092896e-07F;        // smallest such that 1.0+FLT_EPSILON != 1.0  (+1e-4h is NOT good here. is visibly very wrong)
+    float n = (2.0 / max(fEps, m*m)) - 2.0;		// remap to spec power. See eq. 21 in --> https://dl.dropboxusercontent.com/u/55891920/papers/mm_brdf.pdf
+
+    n /= 4;									    // remap from n_dot_h formulatino to n_dot_r. See section "Pre-convolved Cube Maps vs Path Tracers" --> https://s3.amazonaws.com/docs.knaldtech.com/knald/1.0.0/lys_power_drops.html
+
+    perceptualRoughness = pow(2 / (n + 2), 0.25);		// remap back to square root of real roughness (0.25 include both the sqrt root of the conversion and sqrt for going from roughness to perceptualRoughness)
+#else
+    // MM: came up with a surprisingly close approximation to what the #if 0'ed out code above does.
+    perceptualRoughness = perceptualRoughness*(1.7 - 0.7*perceptualRoughness);
+#endif
+
+    return perceptualRoughness * UNITY_SPECCUBE_LOD_STEPS;
+}
+
 // _preIntegratedFG and _CubemapLD are unique for each BRDF
 void EvaluateBSDF_Env(  float3 V, float3 positionWS, PreLightData prelightData, EnvLightData lightData, BSDFData bsdfData,
                         UNITY_ARGS_ENV(_ReflCubeTextures),
     /*
+    if (bsdfData.materialId == MATERIALID_LIT_ANISO)
+    {
+        // Use fake aniso normal
+        // We can overwrite locally the normal without problem
+        bsdfData.normalWS = bsdfData.anisoNormalWS;
+        prelightData.R = prelightData.anisoR;
+    }
+
-    float3 positionLS = mul(float4(positionWS, 1.0), light.invTransform).xyz;
-    float3 dirLS = mul(prelightData.R, (float3x3)light.invTransform);
-    float2 intersections = boxRayIntersect(positionLS, dirLS, -light.extend, light.extend);
+    float3 positionLS = mul(float4(positionWS, 1.0), lightData.invTransform).xyz;
+    float3 dirLS = mul(prelightData.R, (float3x3)lightData.invTransform);
+    float2 intersections = BoxRayIntersect(positionLS, dirLS, -lightData.extend, lightData.extend);
  
     diffuseLighting = float4(0.0, 0.0, 0.0, 1.0);
     specularLighting = float4(0.0, 0.0, 0.0, 1.0);
         // local offset
         R = R - light.localOffset;
 
-        float mipmapLevel = roughnessToMipmapLevel(bsdfData.roughness);
-        half4 rgbm = UNITY_SAMPLE_TEXCUBEARRAY_LOD(tex, float4(glossIn.reflUVW.xyz, sliceIndex), mip);
-        float3 preLD = texCube(_CubemapLD, float4(R, textureIndex), mipmapLevel);
+        float mip = perceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness);
+        R = GetSpecularDominantDir(bsdfData.normalWS, R, bsdfData.roughness);
+
+        float4 preLD = UNITY_SAMPLE_ENV_LOD(tex, float4(R, lightData.sliceIndex), mip);
-
-
+        // Apply specular occlusion on it
-    }*/
+    }
+    */
 
     diffuseLighting = float4(0.0, 0.0, 0.0, 1.0);
     specularLighting = float4(0.0, 0.0, 0.0, 1.0);

Assets/ScriptableRenderLoop/ShaderLibrary/CommonLighting.hlsl

 // Fake anisotropic by distorting the normal as suggested by:
 // Donald Revie - Implementing Fur Using Deferred Shading (GPU Pro 2)
 // anisotropic ratio (0->no isotropic; 1->full anisotropy in tangent direction)
-float3 GetAnisotropicModifiedNormal(float3 normalWS, float3 tangentWS, float3 viewVector, float anisotropy)
+float3 GetAnisotropicModifiedNormal(float3 N, float3 T, float3 V, float anisotropy)
-    float3 anisoTangentWS = cross(-viewVector, tangentWS);
-    float3 anisoNormalWS = cross(anisoTangentWS, tangentWS);
+    float3 anisoT = cross(-V, T);
+    float3 anisoN = cross(anisoT, T);
-    return normalize(lerp(normalWS, anisoNormalWS, anisotropy));
+    return normalize(lerp(N, anisoN, anisotropy));
 }
 
 //-----------------------------------------------------------------------------

Assets/ScriptableRenderLoop/ShaderLibrary/GeometricTools.hlsl

 
 #include "Common.hlsl"
 
+//-----------------------------------------------------------------------------
+// Intersection functions
+//-----------------------------------------------------------------------------
+
+// return furthest near intersection in x and  closest far intersection in y
+float2 BoxRayIntersect(float3 start, float3 dir, float3 boxMin, float3 boxMax)
+{
+    float3 invDir = 1.0 / dir;
+
+    // Find the ray intersection with box plane
+    float3 firstPlaneIntersect = (boxMin - start) * invDir;
+    float3 secondPlaneIntersect = (boxMax - start) * invDir;
+
+    // Get the closest/furthest of these intersections along the ray (Ok because x/0 give +inf and -x/0 give �inf )
+    float3 closestPlane = min(firstPlaneIntersect, secondPlaneIntersect);
+    float3 furthestPlane = max(firstPlaneIntersect, secondPlaneIntersect);
+
+    float2 intersections;
+    // Find the furthest near intersection
+    intersections.x = max(closestPlane.x, max(closestPlane.y, closestPlane.z));
+    // Find the closest far intersection
+    intersections.y = min(min(furthestPlane.x, furthestPlane.y), furthestPlane.z);
+
+    return intersections;
+}
+
+// Sphere is at the origin
+bool SphereRayIntersect(out float2 intersections, float3 start, float3 dir, float radius)
+{
+    float a = dot(dir, dir);
+    float b = dot(dir, start) * 2.0;
+    float c = dot(start, start) - radius * radius;
+    float discriminant = b * b - 4.0 * a * c;
+
+    bool intersect = false;
+    if (discriminant < 0.0 || a == 0.0)
+    {
+        intersections.x = 0.0;
+        intersections.y = 0.0;
+    }
+    else
+    {
+        float sqrtDiscriminant = sqrt(discriminant);
+        intersections.x = (-b - sqrtDiscriminant) / (2.0 * a);
+        intersections.y = (-b + sqrtDiscriminant) / (2.0 * a);
+        intersect = true;
+    }
+
+    return intersect;
+}
+
+float3 RayPlaneIntersect(in float3 rayOrigin, in float3 rayDirection, in float3 planeOrigin, in float3 planeNormal)
+{
+    float dist = dot(planeNormal, planeOrigin - rayOrigin) / dot(planeNormal, rayDirection);
+    return rayOrigin + rayDirection * dist;
+}
+
+//-----------------------------------------------------------------------------
+// Distance functions
+//-----------------------------------------------------------------------------
+
+// Ref: real time detection collision page 131
+float DistanceBoxPoint(float3 boxMin, float3 boxMax, float3 pos)
+{
+    // Clamp to find closest point then calc distance
+    float3 distanceToMin = pos < boxMin ? (boxMin - pos) * (boxMin - pos) : 0.0;
+    float3 distancesToMax = pos > boxMax ? (pos - boxMax) * (pos - boxMax) : 0.0;
+
+    float distanceSquare = dot(distanceToMin, float3(1.0, 1.0, 1.0)) + dot(distancesToMax, float3(1.0, 1.0, 1.0));
+    return sqrt(distanceSquare);
+}
+
 #endif // UNITY_GEOMETRICTOOLS_INCLUDED

Assets/ScriptableRenderLoop/ShaderLibrary/ImageBasedLighting.hlsl

     return float4(acc * (1.0 / accWeight), 1.0);
 }
 
+// Ref: See "Moving Frostbite to PBR" Listing 22
+float3 GetSpecularDominantDir(float3 N, float3 R, float roughness)
+{
+    float a = 1.0 - roughness;
+    float lerpFactor = a * (sqrt(a) + roughness);
+    // The result is not normalized as we fetch in a cubemap
+    return lerp(N, R, lerpFactor);
+}
+
 #endif // UNITY_IMAGE_BASED_LIGHTING_INCLUDED