Fix regression that was introduced in a previous PR on the diffuse denoiser

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -36,6 +36,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed robustness issues with the stacklit material in path tracing (case 1373971).
 - Fixed custom pass injection point not visible in the UI when using the Camera mode.
 - Fixed film grain & dithering when using spatial upscaling methods for DRS.
+- Fixed a regression that was introduced in the diffuse denoiser in a previous PR.
 
 ### Changed
 - Use RayTracingAccelerationStructure.CullInstances to filter Renderers and populate the acceleration structure with ray tracing instances for improved CPU performance on the main thread.

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/HDDiffuseDenoiser.cs

@@ -8,7 +8,6 @@ class HDDiffuseDenoiser
     {
         // Resources used for the de-noiser
         ComputeShader m_DiffuseDenoiser;
-        Texture m_OwenScrambleRGBA;
 
         HDRenderPipeline m_RenderPipeline;
 
@@ -18,20 +17,11 @@ class HDDiffuseDenoiser
         int m_GatherSingleKernel;
         int m_GatherColorKernel;
         ComputeBuffer m_PointDistribution;
-        static internal float[] pointDistribution = new float[] { 0.647285104f, -0.534139216f, 0.201738372f, 0.260410696f,
-                                                                  -0.443308681f, 0.259598345f, 0.0f, 0.0f,
-                                                                    0.851900041f, 0.214261428f, 0.0376310274f, -0.406103343f,
-                                                                    -0.357411921f, -0.525219262f, -0.00147355383f, 0.239211172f,
-                                                                    -0.463947058f, 0.646911025f, -0.0379408896f, -0.291660219f,
-                                                                    0.405679494f, -0.473511368f, 0.0473965593f, 0.0411158539f,
-                                                                    -0.963973522f, -0.155723229f, -0.444706231f, 0.141471207f,
-                                                                    0.0980135575f, 0.687162697f, 0.156328082f, -0.0518609099f};
 
         public void Init(HDRenderPipelineRuntimeResources rpResources, HDRenderPipeline renderPipeline)
         {
             // Keep track of the resources
             m_DiffuseDenoiser = rpResources.shaders.diffuseDenoiserCS;
-            m_OwenScrambleRGBA = rpResources.textures.owenScrambledRGBATex;
 
             m_RenderPipeline = renderPipeline;
 
@@ -40,8 +30,13 @@ public void Init(HDRenderPipelineRuntimeResources rpResources, HDRenderPipeline
             m_BilateralFilterColorKernel = m_DiffuseDenoiser.FindKernel("BilateralFilterColor");
             m_GatherSingleKernel = m_DiffuseDenoiser.FindKernel("GatherSingle");
             m_GatherColorKernel = m_DiffuseDenoiser.FindKernel("GatherColor");
-            m_PointDistribution = new ComputeBuffer(16 * 2, sizeof(float));
-            m_PointDistribution.SetData(pointDistribution);
+
+            // Generate the point distribution
+            int m_GeneratePointDistributionKernel = m_DiffuseDenoiser.FindKernel("GeneratePointDistribution");
+            m_PointDistribution = new ComputeBuffer(16 * 2 * 4, sizeof(float));
+            m_DiffuseDenoiser.SetTexture(m_GeneratePointDistributionKernel, HDShaderIDs._OwenScrambledRGTexture, rpResources.textures.owenScrambledRGBATex);
+            m_DiffuseDenoiser.SetBuffer(m_GeneratePointDistributionKernel, "_PointDistributionRW", m_PointDistribution);
+            m_DiffuseDenoiser.Dispatch(m_GeneratePointDistributionKernel, 1, 1, 1);
         }
 
         public void Release()

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Denoising/DiffuseDenoiser.compute

@@ -1,3 +1,5 @@
+#pragma kernel GeneratePointDistribution
+
 #pragma kernel BilateralFilterSingle        BILATERAL_FILTER=BilateralFilterSingle     SINGLE_CHANNEL
 #pragma kernel BilateralFilterColor         BILATERAL_FILTER=BilateralFilterColor
 
@@ -21,6 +23,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariablesGlobal.cs.hlsl"
 
 // Ray Tracing includes
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RaytracingSampling.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/ShaderVariablesRaytracing.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Denoising/BilateralFilter.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Denoising/DenoisingUtils.hlsl"
@@ -32,6 +35,7 @@
 // Noisy Input Buffer
 TEXTURE2D_X(_DenoiseInputTexture);
 // Buffer used for point sampling
+RWStructuredBuffer<float2> _PointDistributionRW;
 StructuredBuffer<float2> _PointDistribution;
 // Filtered Output buffer (depends on the singel or color variant of the denoiser)
 #if SINGLE_CHANNEL
@@ -50,6 +54,12 @@ int _JitterFramePeriod;
 // Flag used to do a half resolution filter
 int _HalfResolutionFilter;
 
+[numthreads(64, 1, 1)]
+void GeneratePointDistribution(uint3 dispatchThreadId : SV_DispatchThreadID)
+{
+    _PointDistributionRW[dispatchThreadId.x] = SampleDiskCubic(GetLDSequenceSampleFloat(dispatchThreadId.x, 0), GetLDSequenceSampleFloat(dispatchThreadId.x, 1));
+}
+
 float ComputeMaxDenoisingRadius(float3 positionRWS)
 {
     // Compute the distance to the pixel
@@ -127,7 +137,7 @@ void BILATERAL_FILTER(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 groupT
         hClip.xyz /= hClip.w;
 
         // Is the target pixel in the screen?
-        if (hClip.x > 1.0 || hClip.x < -1.0 || hClip.y > 1.0 || hClip.y < -1.0 )
+        if (hClip.x > 1.0 || hClip.x < -1.0 || hClip.y > 1.0 || hClip.y < -1.0)
             continue;
 
         // Convert it to screen sample space