Fixed an issue with the frame count management for the volumetric fog (case 1299251).

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

@@ -30,6 +30,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed computation of geometric normal in path tracing (case 1293029).
 - Fixed issues with path-traced volumetric scattering (cases 1295222, 1295234).
 - Fixed the default background color for previews to use the original color.
+- Fixed an issue with the frame count management for the volumetric fog (case 1299251).
 
 ### Changed
 - Removed the material pass probe volumes evaluation mode.

com.unity.render-pipelines.high-definition/Runtime/Lighting/VolumetricLighting/VolumetricLighting.cs

@@ -270,6 +270,12 @@ static internal void SafeDestroy(ref RenderTexture rt)
             }
         }
 
+        static uint VolumetricFrameIndex(HDCamera hdCamera)
+        {
+            // Here we do modulo 14 because we need the enable to detect a change every frame, but the accumulation is done on 7 frames (7x2=14)
+            return hdCamera.GetCameraFrameCount() % 14;
+        }
+
         static internal Vector3Int ComputeVolumetricViewportSize(HDCamera hdCamera, ref float voxelSize)
         {
             var controller = hdCamera.volumeStack.GetComponent<Fog>();
@@ -356,7 +362,7 @@ static internal void ReinitializeVolumetricBufferParams(HDCamera hdCamera)
 
         // This function relies on being called once per camera per frame.
         // The results are undefined otherwise.
-        static internal void UpdateVolumetricBufferParams(HDCamera hdCamera, int frameIndex)
+        static internal void UpdateVolumetricBufferParams(HDCamera hdCamera)
         {
             if (!Fog.IsVolumetricFogEnabled(hdCamera))
                 return;
@@ -366,6 +372,7 @@ static internal void UpdateVolumetricBufferParams(HDCamera hdCamera, int frameIn
 
             var currentParams = ComputeVolumetricBufferParameters(hdCamera);
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = (frameIndex + 0) & 1;
             var prevIdx = (frameIndex + 1) & 1;
 
@@ -419,7 +426,7 @@ struct GenerateMaxZParameters
         }
 
 
-        GenerateMaxZParameters PrepareGenerateMaxZParameters(HDCamera hdCamera, HDUtils.PackedMipChainInfo depthMipInfo, int frameIndex)
+        GenerateMaxZParameters PrepareGenerateMaxZParameters(HDCamera hdCamera, HDUtils.PackedMipChainInfo depthMipInfo)
         {
             var parameters = new GenerateMaxZParameters();
             parameters.generateMaxZCS = defaultResources.shaders.maxZCS;
@@ -436,6 +443,7 @@ GenerateMaxZParameters PrepareGenerateMaxZParameters(HDCamera hdCamera, HDUtils.
             parameters.minDepthMipOffset.x = depthMipInfo.mipLevelOffsets[4].x;
             parameters.minDepthMipOffset.y = depthMipInfo.mipLevelOffsets[4].y;
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = frameIndex & 1;
             var currentParams = hdCamera.vBufferParams[currIdx];
 
@@ -549,7 +557,7 @@ static internal void DestroyVolumetricHistoryBuffers(HDCamera hdCamera)
 
         // Must be called AFTER UpdateVolumetricBufferParams.
         static readonly string[] volumetricHistoryBufferNames = new string[2] { "VBufferHistory0", "VBufferHistory1" };
-        static internal void ResizeVolumetricHistoryBuffers(HDCamera hdCamera, int frameIndex)
+        static internal void ResizeVolumetricHistoryBuffers(HDCamera hdCamera)
         {
             if (!hdCamera.IsVolumetricReprojectionEnabled())
                 return;
@@ -558,6 +566,7 @@ static internal void ResizeVolumetricHistoryBuffers(HDCamera hdCamera, int frame
             Debug.Assert(hdCamera.vBufferParams.Length == 2);
             Debug.Assert(hdCamera.volumetricHistoryBuffers != null);
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = (frameIndex + 0) & 1;
             var prevIdx = (frameIndex + 1) & 1;
 
@@ -627,7 +636,7 @@ internal void DestroyVolumetricLightingBuffers()
         }
 
         // Must be called AFTER UpdateVolumetricBufferParams.
-        internal void ResizeVolumetricLightingBuffers(HDCamera hdCamera, int frameIndex)
+        internal void ResizeVolumetricLightingBuffers(HDCamera hdCamera)
         {
             if (!Fog.IsVolumetricFogEnabled(hdCamera))
                 return;
@@ -643,6 +652,7 @@ internal void ResizeVolumetricLightingBuffers(HDCamera hdCamera, int frameIndex)
                 CreateVolumetricLightingBuffers();
             }
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = (frameIndex + 0) & 1;
             var prevIdx = (frameIndex + 1) & 1;
 
@@ -819,11 +829,12 @@ unsafe void SetPreconvolvedAmbientLightProbe(ref ShaderVariablesVolumetric cb, H
                     cb._AmbientProbeCoeffs[i * 4 + j] = m_PackedCoeffs[i][j];
         }
 
-        unsafe void UpdateShaderVariableslVolumetrics(ref ShaderVariablesVolumetric cb, HDCamera hdCamera, in Vector4 resolution, int frameIndex)
+        unsafe void UpdateShaderVariableslVolumetrics(ref ShaderVariablesVolumetric cb, HDCamera hdCamera, in Vector4 resolution)
         {
             var fog = hdCamera.volumeStack.GetComponent<Fog>();
             var vFoV = hdCamera.camera.GetGateFittedFieldOfView() * Mathf.Deg2Rad;
             var gpuAspect = HDUtils.ProjectionMatrixAspect(hdCamera.mainViewConstants.projMatrix);
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
 
             // Compose the matrix which allows us to compute the world space view direction.
             hdCamera.GetPixelCoordToViewDirWS(resolution, gpuAspect, ref m_PixelCoordToViewDirWS);
@@ -886,10 +897,11 @@ unsafe void UpdateShaderVariableslVolumetrics(ref ShaderVariablesVolumetric cb,
             cb._NumTileBigTileY = (uint)GetNumTileBigTileY(hdCamera);
         }
 
-        VolumeVoxelizationParameters PrepareVolumeVoxelizationParameters(HDCamera hdCamera, int frameIndex)
+        VolumeVoxelizationParameters PrepareVolumeVoxelizationParameters(HDCamera hdCamera)
         {
             var parameters = new VolumeVoxelizationParameters();
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = (frameIndex + 0) & 1;
             var prevIdx = (frameIndex + 1) & 1;
 
@@ -912,7 +924,7 @@ VolumeVoxelizationParameters PrepareVolumeVoxelizationParameters(HDCamera hdCame
                 parameters.volumeAtlas = CoreUtils.blackVolumeTexture;
             }
 
-            UpdateShaderVariableslVolumetrics(ref m_ShaderVariablesVolumetricCB, hdCamera, parameters.resolution, frameIndex);
+            UpdateShaderVariableslVolumetrics(ref m_ShaderVariablesVolumetricCB, hdCamera, parameters.resolution);
             parameters.volumetricCB = m_ShaderVariablesVolumetricCB;
             parameters.lightListCB = m_ShaderVariablesLightListCB;
 
@@ -992,10 +1004,11 @@ struct VolumetricLightingParameters
             public ShaderVariablesLightList     lightListCB;
         }
 
-        VolumetricLightingParameters PrepareVolumetricLightingParameters(HDCamera hdCamera, int frameIndex)
+        VolumetricLightingParameters PrepareVolumetricLightingParameters(HDCamera hdCamera)
         {
             var parameters = new VolumetricLightingParameters();
 
+            int frameIndex = (int)VolumetricFrameIndex(hdCamera);
             var currIdx = (frameIndex + 0) & 1;
             var prevIdx = (frameIndex + 1) & 1;
 
@@ -1032,7 +1045,7 @@ VolumetricLightingParameters PrepareVolumetricLightingParameters(HDCamera hdCame
             parameters.filterVolume = ((int)fog.denoisingMode.value & (int)FogDenoisingMode.Gaussian) != 0;
             parameters.sliceCount = (int)(cvp.z);
 
-            UpdateShaderVariableslVolumetrics(ref m_ShaderVariablesVolumetricCB, hdCamera, parameters.resolution, frameIndex);
+            UpdateShaderVariableslVolumetrics(ref m_ShaderVariablesVolumetricCB, hdCamera, parameters.resolution);
             parameters.volumetricCB = m_ShaderVariablesVolumetricCB;
             parameters.lightListCB = m_ShaderVariablesLightListCB;
 

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

@@ -573,8 +573,8 @@ internal void Update(FrameSettings currentFrameSettings, HDRenderPipeline hdrp,
             isFirstFrame = false;
             cameraFrameCount++;
 
-            HDRenderPipeline.UpdateVolumetricBufferParams(this, hdrp.GetFrameCount());
-            HDRenderPipeline.ResizeVolumetricHistoryBuffers(this, hdrp.GetFrameCount());
+            HDRenderPipeline.UpdateVolumetricBufferParams(this);
+            HDRenderPipeline.ResizeVolumetricHistoryBuffers(this);
         }
 
         /// <summary>Set the RTHandle scale to the actual camera size (can be scaled)</summary>

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

@@ -600,16 +600,15 @@ TextureHandle VolumeVoxelizationPass(RenderGraph         renderGraph,
             HDCamera            hdCamera,
             ComputeBuffer       visibleVolumeBoundsBuffer,
             ComputeBuffer       visibleVolumeDataBuffer,
-            ComputeBufferHandle bigTileLightList,
-            int                 frameIndex)
+            ComputeBufferHandle bigTileLightList)
         {
             if (Fog.IsVolumetricFogEnabled(hdCamera))
             {
                 using (var builder = renderGraph.AddRenderPass<VolumeVoxelizationPassData>("Volume Voxelization", out var passData))
                 {
                     builder.EnableAsyncCompute(hdCamera.frameSettings.VolumeVoxelizationRunsAsync());
 
-                    passData.parameters = PrepareVolumeVoxelizationParameters(hdCamera, frameIndex);
+                    passData.parameters = PrepareVolumeVoxelizationParameters(hdCamera);
                     passData.visibleVolumeBoundsBuffer = visibleVolumeBoundsBuffer;
                     passData.visibleVolumeDataBuffer = visibleVolumeDataBuffer;
                     if (passData.parameters.tiledLighting)
@@ -657,7 +656,7 @@ TextureHandle GenerateMaxZPass(RenderGraph renderGraph, HDCamera hdCamera, Textu
 
                 using (var builder = renderGraph.AddRenderPass<GenerateMaxZMaskPassData>("Generate Max Z Mask for Volumetric", out var passData))
                 {
-                    passData.parameters = PrepareGenerateMaxZParameters(hdCamera, depthMipInfo, frameIndex);
+                    passData.parameters = PrepareGenerateMaxZParameters(hdCamera, depthMipInfo);
                     passData.depthTexture = builder.ReadTexture(depthTexture);
                     passData.maxZ8xBuffer = builder.ReadTexture(renderGraph.ImportTexture(m_MaxZMask8x));
                     passData.maxZ8xBuffer = builder.WriteTexture(passData.maxZ8xBuffer);
@@ -691,11 +690,12 @@ class VolumetricLightingPassData
             public ComputeBufferHandle          bigTileLightListBuffer;
         }
 
-        TextureHandle VolumetricLightingPass(RenderGraph renderGraph, HDCamera hdCamera, TextureHandle depthTexture, TextureHandle densityBuffer, TextureHandle maxZBuffer, ComputeBufferHandle bigTileLightListBuffer, ShadowResult shadowResult, int frameIndex)
+        TextureHandle VolumetricLightingPass(RenderGraph renderGraph, HDCamera hdCamera, TextureHandle depthTexture, TextureHandle densityBuffer, TextureHandle maxZBuffer, ComputeBufferHandle bigTileLightListBuffer, ShadowResult shadowResult)
         {
             if (Fog.IsVolumetricFogEnabled(hdCamera))
             {
-                var parameters = PrepareVolumetricLightingParameters(hdCamera, frameIndex);
+                // Evaluate the parameters
+                var parameters = PrepareVolumetricLightingParameters(hdCamera);
 
                 using (var builder = renderGraph.AddRenderPass<VolumetricLightingPassData>("Volumetric Lighting", out var passData))
                 {
@@ -717,6 +717,7 @@ TextureHandle VolumetricLightingPass(RenderGraph renderGraph, HDCamera hdCamera,
 
                     if (passData.parameters.enableReprojection)
                     {
+                        int frameIndex = (int)VolumetricFrameIndex(hdCamera);
                         var currIdx = (frameIndex + 0) & 1;
                         var prevIdx = (frameIndex + 1) & 1;
 

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

@@ -103,7 +103,7 @@ void ExecuteWithRenderGraph(RenderRequest           renderRequest,
 
                 lightingBuffers.contactShadowsBuffer = RenderContactShadows(m_RenderGraph, hdCamera, msaa ? prepassOutput.depthValuesMSAA : prepassOutput.depthPyramidTexture, gpuLightListOutput, GetDepthBufferMipChainInfo().mipLevelOffsets[1].y);
 
-                var volumetricDensityBuffer = VolumeVoxelizationPass(m_RenderGraph, hdCamera, m_VisibleVolumeBoundsBuffer, m_VisibleVolumeDataBuffer, gpuLightListOutput.bigTileLightList, m_FrameCount);
+                var volumetricDensityBuffer = VolumeVoxelizationPass(m_RenderGraph, hdCamera, m_VisibleVolumeBoundsBuffer, m_VisibleVolumeDataBuffer, gpuLightListOutput.bigTileLightList);
 
                 RenderShadows(m_RenderGraph, hdCamera, cullingResults, ref shadowResult);
 
@@ -146,7 +146,7 @@ void ExecuteWithRenderGraph(RenderRequest           renderRequest,
 
                 var maxZMask = GenerateMaxZPass(m_RenderGraph, hdCamera, prepassOutput.depthPyramidTexture, m_DepthBufferMipChainInfo, m_FrameCount);
 
-                var volumetricLighting = VolumetricLightingPass(m_RenderGraph, hdCamera, prepassOutput.depthPyramidTexture, volumetricDensityBuffer, maxZMask, gpuLightListOutput.bigTileLightList, shadowResult, m_FrameCount);
+                var volumetricLighting = VolumetricLightingPass(m_RenderGraph, hdCamera, prepassOutput.depthPyramidTexture, volumetricDensityBuffer, maxZMask, gpuLightListOutput.bigTileLightList, shadowResult);
 
                 var deferredLightingOutput = RenderDeferredLighting(m_RenderGraph, hdCamera, colorBuffer, prepassOutput.depthBuffer, prepassOutput.depthPyramidTexture, lightingBuffers, prepassOutput.gbuffer, shadowResult, gpuLightListOutput);
 

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

@@ -2299,7 +2299,7 @@ out ScriptableCullingParameters cullingParams
 
             // From this point, we should only use frame settings from the camera
             hdCamera.Update(currentFrameSettings, this, m_MSAASamples, xrPass);
-            ResizeVolumetricLightingBuffers(hdCamera, GetFrameCount()); // Safe to update the Volumetric Lighting System now
+            ResizeVolumetricLightingBuffers(hdCamera); // Safe to update the Volumetric Lighting System now
 
             // Custom Render requires a proper HDCamera, so we return after the HDCamera was setup
             if (additionalCameraData != null && additionalCameraData.hasCustomRender)