Merge pull request #939 from Unity-Technologies/feature/MergeSSRefractionAndSSReflection

Merging SSRefraction and SSReflection functions

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/LightLoop.hlsl

 
     if (featureFlags & LIGHTFEATUREFLAGS_SSREFRACTION)
     {
-        IndirectLighting lighting = EvaluateBSDF_SSRefraction(context, V, posInput, preLightData, bsdfData, refractionHierarchyWeight);
+        IndirectLighting lighting = EvaluateBSDF_SSLighting(
+            context,
+            V,
+            posInput,
+            preLightData,
+            bsdfData,
+            GPUIMAGEBASEDLIGHTINGTYPE_REFRACTION,
+            refractionHierarchyWeight);
-        IndirectLighting lighting = EvaluateBSDF_SSReflection(context, V, posInput, preLightData, bsdfData, reflectionHierarchyWeight);
+        IndirectLighting lighting = EvaluateBSDF_SSLighting(
+            context,
+            V,
+            posInput,
+            preLightData,
+            bsdfData,
+            GPUIMAGEBASEDLIGHTINGTYPE_REFLECTION,
+            reflectionHierarchyWeight);
         AccumulateIndirectLighting(lighting, aggregateLighting);
     }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl

 // EvaluateBSDF_SSLighting for screen space lighting
 // ----------------------------------------------------------------------------
 
-IndirectLighting EvaluateBSDF_SSReflection(LightLoopContext lightLoopContext,
-                                            float3 V, PositionInputs posInput,
-                                            PreLightData preLightData, BSDFData bsdfData,
-                                            inout float hierarchyWeight)
-{
-    IndirectLighting lighting;
-    ZERO_INITIALIZE(IndirectLighting, lighting);
-
-    // TODO
-
-    return lighting;
-}
-
-IndirectLighting EvaluateBSDF_SSRefraction(LightLoopContext lightLoopContext,
+IndirectLighting EvaluateBSDF_SSLighting(LightLoopContext lightLoopContext,
+                                            int GPUImageBasedLightingType,
+    switch (GPUImageBasedLightingType)
+    {
+        case GPUIMAGEBASEDLIGHTINGTYPE_REFRACTION:
+        {
-    // Refraction process:
-    //  1. Depending on the shape model, we calculate the refracted point in world space and the optical depth
-    //  2. We calculate the screen space position of the refracted point
-    //  3. If this point is available (ie: in color buffer and point is not in front of the object)
-    //    a. Get the corresponding color depending on the roughness from the gaussian pyramid of the color buffer
-    //    b. Multiply by the transmittance for absorption (depends on the optical depth)
+            // Refraction process:
+            //  1. Depending on the shape model, we calculate the refracted point in world space and the optical depth
+            //  2. We calculate the screen space position of the refracted point
+            //  3. If this point is available (ie: in color buffer and point is not in front of the object)
+            //    a. Get the corresponding color depending on the roughness from the gaussian pyramid of the color buffer
+            //    b. Multiply by the transmittance for absorption (depends on the optical depth)
-    float3 refractedBackPointWS = EstimateRaycast(V, posInput, preLightData.transparentPositionWS, preLightData.transparentRefractV);
+            float3 refractedBackPointWS = EstimateRaycast(V, posInput, preLightData.transparentPositionWS, preLightData.transparentRefractV);
-    // Calculate screen space coordinates of refracted point in back plane
-    float2 refractedBackPointNDC = ComputeNormalizedDeviceCoordinates(refractedBackPointWS, UNITY_MATRIX_VP);
-    uint2 depthSize = uint2(_PyramidDepthMipSize.xy);
-    float refractedBackPointDepth = LinearEyeDepth(LOAD_TEXTURE2D_LOD(_PyramidDepthTexture, refractedBackPointNDC * depthSize, 0).r, _ZBufferParams);
+            // Calculate screen space coordinates of refracted point in back plane
+            float2 refractedBackPointNDC = ComputeNormalizedDeviceCoordinates(refractedBackPointWS, UNITY_MATRIX_VP);
+            uint2 depthSize = uint2(_PyramidDepthMipSize.xy);
+            float refractedBackPointDepth = LinearEyeDepth(LOAD_TEXTURE2D_LOD(_PyramidDepthTexture, refractedBackPointNDC * depthSize, 0).r, _ZBufferParams);
-    // Exit if texel is out of color buffer
-    // Or if the texel is from an object in front of the object
-    if (refractedBackPointDepth < posInput.linearDepth
-        || any(refractedBackPointNDC < 0.0)
-        || any(refractedBackPointNDC > 1.0))
-    {
-        // Do nothing and don't update the hierarchy weight so we can fall back on refraction probe
-        return lighting;
-    }
+            // Exit if texel is out of color buffer
+            // Or if the texel is from an object in front of the object
+            if (refractedBackPointDepth < posInput.linearDepth
+                || any(refractedBackPointNDC < 0.0)
+                || any(refractedBackPointNDC > 1.0))
+            {
+                // Do nothing and don't update the hierarchy weight so we can fall back on refraction probe
+                return lighting;
+            }
-    // Map the roughness to the correct mip map level of the color pyramid
-    lighting.specularTransmitted = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, refractedBackPointNDC * _GaussianPyramidColorMipSize.xy, preLightData.transparentSSMipLevel).rgb;
+            // Map the roughness to the correct mip map level of the color pyramid
+            lighting.specularTransmitted = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, refractedBackPointNDC * _GaussianPyramidColorMipSize.xy, preLightData.transparentSSMipLevel).rgb;
-    // Beer-Lamber law for absorption
-    lighting.specularTransmitted *= preLightData.transparentTransmittance;
+            // Beer-Lamber law for absorption
+            lighting.specularTransmitted *= preLightData.transparentTransmittance;
-    float weight = 1.0;
-    UpdateLightingHierarchyWeights(hierarchyWeight, weight); // Shouldn't be needed, but safer in case we decide to change hierarchy priority
-    // We use specularFGD as an approximation of the fresnel effect (that also handle smoothness), so take the remaining for transmission
-    lighting.specularTransmitted *= (1.0 - preLightData.specularFGD) * weight;
+            float weight = 1.0;
+            UpdateLightingHierarchyWeights(hierarchyWeight, weight); // Shouldn't be needed, but safer in case we decide to change hierarchy priority
+                                                                     // We use specularFGD as an approximation of the fresnel effect (that also handle smoothness), so take the remaining for transmission
+            lighting.specularTransmitted *= (1.0 - preLightData.specularFGD) * weight;
-    // No refraction, no need to go further
-    hierarchyWeight = 1.0;
+            // No refraction, no need to go further
+            hierarchyWeight = 1.0;
+            break;
+        }
+        case GPUIMAGEBASEDLIGHTINGTYPE_REFLECTION:
+        {
+            break;
+        }
+    }
 
     return lighting;
 }