Fixing the intensity being applied to RTAO too early leading to unexpected results (1254626).

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

@@ -672,6 +672,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed an issue where rendering preview with MSAA might generate render graph errors.
 - Fixed compile error in PS4 for planar reflection filtering.
 - Fixed issue with blue line in prefabs for volume mode.
+- Fixing the internsity being applied to RTAO too early leading to unexpected results (1254626).
 
 ### Changed
 - Improve MIP selection for decals on Transparents

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

@@ -43,7 +43,9 @@ partial class HDRenderPipelineRayTracingResources : ScriptableObject
 
         // Ambient Occlusion
         [Reload("Runtime/RenderPipeline/Raytracing/Shaders/RaytracingAmbientOcclusion.raytrace")]
-        public RayTracingShader aoRaytracing;
+        public RayTracingShader aoRaytracingRT;
+        [Reload("Runtime/RenderPipeline/Raytracing/Shaders/RaytracingAmbientOcclusion.compute")]
+        public ComputeShader aoRaytracingCS;
 
         // Sub-Surface Scattering
         [Reload("Runtime/RenderPipeline/Raytracing/Shaders/RayTracingSubSurface.raytrace")]

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

@@ -12,6 +12,7 @@ internal class HDRaytracingAmbientOcclusion
 
         // The target denoising kernel
         static int m_KernelFilter;
+        static int m_RTAOApplyIntensityKernel;
 
         // Intermediate buffer that stores the ambient occlusion pre-denoising
         RTHandle m_AOIntermediateBuffer0 = null;
@@ -36,6 +37,9 @@ public void Init(HDRenderPipeline renderPipeline)
             // keep track of the render pipeline
             m_RenderPipeline = renderPipeline;
 
+            // Grab the kernels we need
+            m_RTAOApplyIntensityKernel = m_PipelineRayTracingResources.aoRaytracingCS.FindKernel("RTAOApplyIntensity");
+
             // Allocate the intermediate textures
             m_AOIntermediateBuffer0 = RTHandles.Alloc(Vector2.one, TextureXR.slices, colorFormat: GraphicsFormat.R16G16B16A16_SFloat, dimension: TextureXR.dimension, enableRandomWrite: true, useDynamicScale: true, useMipMap: false, autoGenerateMips: false, name: "AOIntermediateBuffer0");
             m_AOIntermediateBuffer1 = RTHandles.Alloc(Vector2.one, TextureXR.slices, colorFormat: GraphicsFormat.R16G16B16A16_SFloat, dimension: TextureXR.dimension, enableRandomWrite: true, useDynamicScale: true, useMipMap: false, autoGenerateMips: false, name: "AOIntermediateBuffer1");
@@ -69,7 +73,7 @@ public void RenderAO(HDCamera hdCamera, CommandBuffer cmd, RTHandle outputTextur
                 return;
             }
 
-            RayTracingShader aoShader = m_PipelineRayTracingResources.aoRaytracing;
+            RayTracingShader aoShaderRT = m_PipelineRayTracingResources.aoRaytracingRT;
             var aoSettings = hdCamera.volumeStack.GetComponent<AmbientOcclusion>();
             RayCountManager rayCountManager = m_RenderPipeline.GetRayCountManager();
 
@@ -79,33 +83,31 @@ public void RenderAO(HDCamera hdCamera, CommandBuffer cmd, RTHandle outputTextur
                 RayTracingAccelerationStructure accelerationStructure = m_RenderPipeline.RequestAccelerationStructure();
 
                 // Define the shader pass to use for the reflection pass
-                cmd.SetRayTracingShaderPass(aoShader, "VisibilityDXR");
+                cmd.SetRayTracingShaderPass(aoShaderRT, "VisibilityDXR");
 
                 // Set the acceleration structure for the pass
-                cmd.SetRayTracingAccelerationStructure(aoShader, HDShaderIDs._RaytracingAccelerationStructureName, accelerationStructure);
+                cmd.SetRayTracingAccelerationStructure(aoShaderRT, HDShaderIDs._RaytracingAccelerationStructureName, accelerationStructure);
 
                 // Inject the ray generation data (be careful of the global constant buffer limitation)
                 globalCB._RaytracingRayMaxLength = aoSettings.rayLength;
                 globalCB._RaytracingNumSamples = aoSettings.sampleCount;
                 ConstantBuffer.PushGlobal(cmd, globalCB, HDShaderIDs._ShaderVariablesRaytracing);
 
                 // Set the data for the ray generation
-                cmd.SetRayTracingTextureParam(aoShader, HDShaderIDs._DepthTexture, m_RenderPipeline.sharedRTManager.GetDepthStencilBuffer());
-                cmd.SetRayTracingTextureParam(aoShader, HDShaderIDs._NormalBufferTexture, m_RenderPipeline.sharedRTManager.GetNormalBuffer());
+                cmd.SetRayTracingTextureParam(aoShaderRT, HDShaderIDs._DepthTexture, m_RenderPipeline.sharedRTManager.GetDepthStencilBuffer());
+                cmd.SetRayTracingTextureParam(aoShaderRT, HDShaderIDs._NormalBufferTexture, m_RenderPipeline.sharedRTManager.GetNormalBuffer());
 
                 // Inject the ray-tracing sampling data
                 BlueNoise blueNoise = m_RenderPipeline.GetBlueNoiseManager();
                 blueNoise.BindDitheredRNGData8SPP(cmd);
 
-                // Value used to scale the ao intensity
-                cmd.SetRayTracingFloatParam(aoShader, HDShaderIDs._RaytracingAOIntensity, aoSettings.intensity.value);
 
                 // Set the output textures
-                cmd.SetRayTracingTextureParam(aoShader, HDShaderIDs._RayCountTexture, rayCountManager.GetRayCountTexture());
-                cmd.SetRayTracingTextureParam(aoShader, HDShaderIDs._AmbientOcclusionTextureRW, m_AOIntermediateBuffer0);
+                cmd.SetRayTracingTextureParam(aoShaderRT, HDShaderIDs._RayCountTexture, rayCountManager.GetRayCountTexture());
+                cmd.SetRayTracingTextureParam(aoShaderRT, HDShaderIDs._AmbientOcclusionTextureRW, m_AOIntermediateBuffer0);
 
                 // Run the computation
-                cmd.DispatchRays(aoShader, m_RayGenShaderName, (uint)hdCamera.actualWidth, (uint)hdCamera.actualHeight, (uint)hdCamera.viewCount);
+                cmd.DispatchRays(aoShaderRT, m_RayGenShaderName, (uint)hdCamera.actualWidth, (uint)hdCamera.actualHeight, (uint)hdCamera.viewCount);
             }
 
             using (new ProfilingScope(cmd, ProfilingSampler.Get(HDProfileId.RaytracingFilterAmbientOcclusion)))
@@ -137,6 +139,16 @@ public void RenderAO(HDCamera hdCamera, CommandBuffer cmd, RTHandle outputTextur
                 {
                     HDUtils.BlitCameraTexture(cmd, m_AOIntermediateBuffer0, outputTexture);
                 }
+
+                ComputeShader aoShaderCS = m_PipelineRayTracingResources.aoRaytracingCS;
+                cmd.SetComputeFloatParam(aoShaderCS, HDShaderIDs._RaytracingAOIntensity, aoSettings.intensity.value);
+                cmd.SetComputeTextureParam(aoShaderCS, m_RTAOApplyIntensityKernel, HDShaderIDs._AmbientOcclusionTextureRW, outputTexture);
+                int texWidth = hdCamera.actualWidth;
+                int texHeight = hdCamera.actualHeight;
+                int areaTileSize = 8;
+                int numTilesXHR = (texWidth + (areaTileSize - 1)) / areaTileSize;
+                int numTilesYHR = (texHeight + (areaTileSize - 1)) / areaTileSize;
+                cmd.DispatchCompute(aoShaderCS, m_RTAOApplyIntensityKernel, numTilesXHR, numTilesYHR, hdCamera.viewCount);
             }
 
             // Bind the textures and the params

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

@@ -0,0 +1,30 @@
+#pragma kernel RTAOApplyIntensity
+
+#pragma only_renderers d3d11
+
+// HDRP generic includes
+#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
+#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariables.hlsl"
+
+#pragma only_renderers d3d11
+// #pragma enable_d3d11_debug_symbols
+
+// Tile size of this compute
+#define RAYTRACING_AMBIENT_OCCLUSION_TILE_SIZE 8
+
+float4  _RaytracingAOIntensity;
+RW_TEXTURE2D_X(float, _AmbientOcclusionTextureRW);
+
+[numthreads(RAYTRACING_AMBIENT_OCCLUSION_TILE_SIZE, RAYTRACING_AMBIENT_OCCLUSION_TILE_SIZE, 1)]
+void RTAOApplyIntensity(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 groupThreadId : SV_GroupThreadID, uint2 groupId : SV_GroupID)
+{
+    UNITY_XR_ASSIGN_VIEW_INDEX(dispatchThreadId.z);
+
+    // Compute the pixel position to process
+    uint2 currentCoord = groupId * RAYTRACING_AMBIENT_OCCLUSION_TILE_SIZE + groupThreadId;
+
+    // Grab the AO value without the intensity
+    float value = _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentCoord)];
+    _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentCoord)] = 1.0 - pow(value, _RaytracingAOIntensity);
+}

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RaytracingAmbientOcclusion.raytrace

@@ -20,8 +20,7 @@
 TEXTURE2D_X(_DepthTexture);
 
 // Output structure of the reflection raytrace shader
-float                                   _RaytracingAOIntensity;
-RW_TEXTURE2D_X(float4, _AmbientOcclusionTextureRW);
+RW_TEXTURE2D_X(float, _AmbientOcclusionTextureRW);
 
 [shader("miss")]
 void MissShaderAmbientOcclusion(inout RayIntersection rayIntersection : SV_RayPayload)
@@ -41,7 +40,7 @@ void RayGenAmbientOcclusion()
     uint2 currentPixelCoord = uint2(LaunchIndex.x, LaunchIndex.y);
 
     // Reset the value of this pixel
-    _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentPixelCoord)] = float4(0.0f, 0.0f, 0.0f, 0.0f);
+    _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentPixelCoord)] = 0.0f;
 
 	// Read the depth value
 	float depthValue  = LOAD_TEXTURE2D_X(_DepthTexture, currentPixelCoord).r;
@@ -67,7 +66,7 @@ void RayGenAmbientOcclusion()
     }
 
 	// Variable that accumulate the radiance
-	float3 finalColor = float3(0.0, 0.0, 0.0);
+	float finalColor = 0.0;
 
 	// Let's loop through th e samples
 	for (int i = 0; i < numSamples; ++i)
@@ -102,17 +101,14 @@ void RayGenAmbientOcclusion()
 		TraceRay(_RaytracingAccelerationStructure, RAY_FLAG_CULL_BACK_FACING_TRIANGLES, RAYTRACINGRENDERERFLAG_AMBIENT_OCCLUSION, 0, 1, 0, rayDescriptor, rayIntersection);
 
 		// Accumulate this value
-		finalColor += rayIntersection.color;
+		finalColor += rayIntersection.color.x;
 	}
 
 	// Normalize the radiance
 	finalColor /= (float)numSamples;
 
-	// Apply our intensity modifier
-	finalColor = pow(finalColor, _RaytracingAOIntensity);
-
 	// Alright we are done
-    _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentPixelCoord)] = float4(1.0 - finalColor, 1.0f);
+    _AmbientOcclusionTextureRW[COORD_TEXTURE2D_X(currentPixelCoord)] = finalColor;
 }
 
 // Fallback default any hit shader for this raytrace shader

com.unity.render-pipelines.high-definition/Runtime/RenderPipelineResources/HDRenderPipelineRayTracingResources.asset

@@ -26,16 +26,16 @@ MonoBehaviour:
   shadowFilterCS: {fileID: 7200000, guid: f71fd853a538bf74e9e5a7228fc14dae, type: 3}
   forwardRaytracing: {fileID: 4807578003741378534, guid: d3a89a2d3f73b3e4da6f191e844fe68c,
     type: 3}
-  raytracingFlagMask: {fileID: 4800000, guid: 7822c8a69a1f21144a20cf6d84e5e706, type: 3}
   lightClusterBuildCS: {fileID: 7200000, guid: c0625ea908b52854bbf1d456e34026e4, type: 3}
   lightClusterDebugS: {fileID: 4800000, guid: c4d81c6e573560444bb1ea11ae4acfcb, type: 3}
   lightClusterDebugCS: {fileID: 7200000, guid: d48a3a5496d98a44c89f335934805d10, type: 3}
   indirectDiffuseRaytracingRT: {fileID: 4807578003741378534, guid: f9b74dc8a89fc7c489e244f0be35baa8,
     type: 3}
   indirectDiffuseRaytracingCS: {fileID: 7200000, guid: c5ad968b7cd39114d85dd860b3809087,
     type: 3}
-  aoRaytracing: {fileID: 4807578003741378534, guid: 82dc8cd069971d2488c502b0f32b94fb,
+  aoRaytracingRT: {fileID: 4807578003741378534, guid: 82dc8cd069971d2488c502b0f32b94fb,
     type: 3}
+  aoRaytracingCS: {fileID: 7200000, guid: 10c05366baf9b0a44a827f3ef890b9e6, type: 3}
   subSurfaceRayTracing: {fileID: 4807578003741378534, guid: b29a18f967c92364492508dddf78cff7,
     type: 3}
   subSurfaceRayTracingCS: {fileID: 7200000, guid: 4e5684a8dba46fe42a47642f9b0a6b89,