Fixed the condition on temporal accumulation in the reflection denoiser (case 1303504).

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

@@ -33,6 +33,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed an issue with half res ssgi upscale.
 - Fixed Clearcoat on Stacklit or Lit breaks when URP is imported into the project (case 1297806)
 - Fixed timing issues with accumulation motion blur
+- Fixed the condition on temporal accumulation in the reflection denoiser (case 1303504).
 
 ### Changed
 - Removed the material pass probe volumes evaluation mode.

com.unity.render-pipelines.high-definition/Runtime/Lighting/ScreenSpaceLighting/SSGIDenoiser.compute

@@ -16,6 +16,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/Builtin/BuiltinData.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.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"
 
 // #pragma only_renderers d3d11
 // #pragma enable_d3d11_debug_symbols
@@ -43,10 +44,6 @@ RW_TEXTURE2D_X(float4, _OutputFilteredBuffer1);
 #define SPATIAL_FILTER_SIGMA_RATIO 0.9
 #define DEPTH_WEIGHT_MULTIPLIER 100.0f
 #define NORMAL_WEIGHT_MULTIPLIER 5.0
-// The maximal world space distance for temporal reprojection
-#define MAX_WORLD_SPACE_DISTANCE 0.1
-// The maximal pixel reprojection distance
-#define PIXEL_RADIUS_TOLERANCE_THRESHOLD 4
 
 // Number of samples to compelte the accumulation loop
 #define NUM_SAMPLE_LOOP 8.0
@@ -234,10 +231,7 @@ void TEMPORAL_FILTER(uint3 dispatchThreadId : SV_DispatchThreadID
     DecodeFromNormalBuffer(centerCoord, normalData);
 
     // Compute the max reprojection distance. This is evaluated as the max between a fixed radius value and an approximation of the footprint of the pixel.
-    const float3 viewWS = GetWorldSpaceNormalizeViewDir(posInputs.positionWS);
-    float parallelPixelFootPrint = _PixelSpreadAngleTangent * length(posInputs.positionWS);
-    float realPixelFootPrint = parallelPixelFootPrint / abs(dot(normalData.normalWS, viewWS));
-    float maxRadius = max(MAX_WORLD_SPACE_DISTANCE, realPixelFootPrint * PIXEL_RADIUS_TOLERANCE_THRESHOLD);
+    float maxRadius = ComputeMaxReprojectionWorldRadius(posInputs.positionWS, normalData.normalWS, _PixelSpreadAngleTangent);
 
     // Is it too far from the current position?
     if (length(historyPositionWS - posInputs.positionWS) > maxRadius)

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Denoising/DenoisingUtils.hlsl

@@ -0,0 +1,16 @@
+
+#define MAX_REPROJECTION_DISTANCE 0.1
+#define MAX_PIXEL_TOLERANCE 4
+
+float ComputeMaxReprojectionWorldRadius(float3 positionWS, float3 normalWS, float pixelSpreadAngleTangent, float maxDistance, float pixelTolerance)
+{
+    const float3 viewWS = GetWorldSpaceNormalizeViewDir(positionWS);
+    float parallelPixelFootPrint = pixelSpreadAngleTangent * length(positionWS);
+    float realPixelFootPrint = parallelPixelFootPrint / abs(dot(normalWS, viewWS));
+    return max(maxDistance, realPixelFootPrint * pixelTolerance);
+}
+
+float ComputeMaxReprojectionWorldRadius(float3 positionWS, float3 normalWS, float pixelSpreadAngleTangent)
+{
+    return ComputeMaxReprojectionWorldRadius(positionWS, normalWS, pixelSpreadAngleTangent, MAX_REPROJECTION_DISTANCE, MAX_PIXEL_TOLERANCE);
+}

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

@@ -22,6 +22,7 @@
 #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"
 
 // Tile size of this compute shaders
 #define DIFFUSE_DENOISER_TILE_SIZE 8
@@ -80,11 +81,7 @@ void BILATERAL_FILTER(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 groupT
     #endif
 
     // Compute the radius of the filter. This is evaluated as the max between a fixed radius value and an approximation of the footprint of the pixel
-    const float parallelPixelFootPrint = _PixelSpreadAngleTangent * length(center.position);
-    // Compute the view in world space
-    const float3 viewWS = GetWorldSpaceNormalizeViewDir(center.position);
-    const float realPixelFootPrint = parallelPixelFootPrint / abs(dot(center.normal, viewWS));
-    const float denoisingRadius = max(_DenoiserFilterRadius, realPixelFootPrint * PIXEL_RADIUS_TOLERANCE_THRESHOLD);
+    const float denoisingRadius = ComputeMaxReprojectionWorldRadius(center.position, center.normal, _PixelSpreadAngleTangent, _DenoiserFilterRadius, PIXEL_RADIUS_TOLERANCE_THRESHOLD);
 
     // Compute the sigma value
     const float sigma = 0.9 * denoisingRadius;

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

@@ -17,6 +17,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl"
 #define BILATERAL_ROUGHNESS
 #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"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/ShaderVariablesRaytracing.cs.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RayTracingCommon.hlsl"
 
@@ -126,8 +127,11 @@ void TEMPORAL_ACCUMULATION(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 g
         // Compute the world space position (from previous frame)
         float3 historyPositionWS = ComputeWorldSpacePosition(posInput.positionNDC - velocity, historyDepth, UNITY_MATRIX_PREV_I_VP);
 
+        // Compute the max world radius that we consider acceptable for history reprojection
+        float maxRadius = ComputeMaxReprojectionWorldRadius(posInput.positionWS, normalData.normalWS, _PixelSpreadAngleTangent);
+
         // Is it too far from the current position?
-        if (length(historyPositionWS - posInput.positionWS) > 0.1)
+        if (length(historyPositionWS - posInput.positionWS) > maxRadius)
             canBeReprojected = false;
 
         if (canBeReprojected && sampleCount != 0.0)

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

@@ -23,6 +23,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/NormalBuffer.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/Builtin/BuiltinData.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl"
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Denoising/DenoisingUtils.hlsl"
 
 #pragma only_renderers d3d11
 // #pragma enable_d3d11_debug_symbols
@@ -45,10 +46,6 @@ float _PixelSpreadAngleTangent;
 // Value that tells us if the current history should be discarded based on scene-level data
 float _HistoryValidity;
 
-// The maximal world space distance for temporal reprojection
-#define MAX_WORLD_SPACE_DISTANCE 0.1
-// The maximal pixel reprojection distance
-#define PIXEL_RADIUS_TOLERANCE_THRESHOLD 4
 // The maximal normal difference threshold
 #define MAX_NORMAL_DIFFERENCE 0.65
 // The minimal motion distance
@@ -95,7 +92,6 @@ void ValidateHistory(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 groupTh
         return;
     }
 
-
     // Real the normal data for this pixel
     NormalData normalData;
     DecodeFromNormalBuffer(centerCoord, normalData);
@@ -104,10 +100,7 @@ void ValidateHistory(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 groupTh
     float3 historyPositionWS = ComputeWorldSpacePosition(posInputs.positionNDC - velocity, historyDepth, UNITY_MATRIX_PREV_I_VP);
 
     // Compute the max reprojection distance. This is evaluated as the max between a fixed radius value and an approximation of the footprint of the pixel.
-    const float3 viewWS = GetWorldSpaceNormalizeViewDir(posInputs.positionWS);
-    float parallelPixelFootPrint = _PixelSpreadAngleTangent * length(posInputs.positionWS);
-    float realPixelFootPrint = parallelPixelFootPrint / abs(dot(normalData.normalWS, viewWS));
-    float maxRadius = max(MAX_WORLD_SPACE_DISTANCE, realPixelFootPrint * PIXEL_RADIUS_TOLERANCE_THRESHOLD);
+    float maxRadius = ComputeMaxReprojectionWorldRadius(posInputs.positionWS, normalData.normalWS, _PixelSpreadAngleTangent);
 
     // Is it too far from the current position?
     if (length(historyPositionWS - posInputs.positionWS) > maxRadius)