Fix wobble-like (or tearing-like) SSAO issues when temporal reprojection is enabled.

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

@@ -267,6 +267,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed HDRP material upgrade failing when there is a texture inside the builtin resources assigned in the material (case 1339865).
 - Fixed custom pass volume not executed in scene view because of the volume culling mask.
 - Fixed remapping of depth pyramid debug view
+- Fix wobbling/tearing-like artifacts with SSAO.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard

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

@@ -2,29 +2,29 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/NormalBuffer.hlsl"
 
 #pragma kernel TemporalDenoise
-
 #pragma multi_compile HALF_RES FULL_RES
 
-uint PackHistoryData(float AO, float depth, float mvLen)
+
+float4 PackHistoryData(float AO, float depth, float mvLen)
 {
-    uint packedVal = 0;
-    packedVal = BitFieldInsert(0x000000ff, UnpackInt(AO, 8), packedVal);
-    packedVal = BitFieldInsert(0x0000ff00, UnpackInt(mvLen, 8) << 8, packedVal);
-    packedVal = BitFieldInsert(0xffff0000, UnpackInt(depth, 16) << 16, packedVal);
-    return packedVal;
+    float4 finalHistory;
+    finalHistory.xy = PackFloatToR8G8(depth);
+    finalHistory.z = saturate(AO);
+    finalHistory.w = saturate(mvLen);
+    return finalHistory;
 }
 
-void UnpackHistoryData(uint historyData, out float AO, out float depth, out float mvLen)
+void UnpackHistoryData(float4 historyData, out float AO, out float depth, out float mvLen)
 {
-    AO = UnpackUIntToFloat(historyData, 0, 8);
-    mvLen = UnpackUIntToFloat(historyData, 8, 8);
-    depth = UnpackUIntToFloat(historyData, 16, 16);
+    AO = historyData.z;
+    mvLen = saturate(historyData.w);
+    depth = UnpackFloatFromR8G8(historyData.xy);
 }
 
-RW_TEXTURE2D_X(uint, _AOOutputHistory);
+RW_TEXTURE2D_X(float4, _AOOutputHistory);
 
 TEXTURE2D_X(_AOPackedBlurred);
-TEXTURE2D_X_UINT(_AOPackedHistory);
+TEXTURE2D_X(_AOPackedHistory);
 RW_TEXTURE2D_X(float, _OcclusionTexture);
 
 float3 FindMinMaxAvgAO(float2 centralPos)
@@ -67,11 +67,12 @@ void TemporalDenoise(uint3 dispatchThreadId : SV_DispatchThreadID)
     float2 motionVector;
     DecodeMotionVector(LOAD_TEXTURE2D_X(_CameraMotionVectorsTexture, closest), motionVector);
     float motionVecLength = length(motionVector);
+    float4 prevData = 0;
 
-    float2 uv = (dispatchThreadId.xy + 0.5) * _AOBufferSize.zw;
+    float2 uv = ((dispatchThreadId.xy + 0.5) * _AOBufferSize.zw);
     float2 prevFrameNDC = uv - motionVector;
 
-    uint prevData = asuint(_AOPackedHistory[COORD_TEXTURE2D_X((prevFrameNDC) * _AOHistorySize.xy)].x);
+    prevData = (SAMPLE_TEXTURE2D_X_LOD(_AOPackedHistory, s_linear_clamp_sampler, (prevFrameNDC) * _RTHandleScaleHistory.zw, 0));
     float prevMotionVecLen, prevAO, prevDepth;
     UnpackHistoryData(prevData, prevAO, prevDepth, prevMotionVecLen);
 

com.unity.render-pipelines.high-definition/Runtime/Lighting/ScreenSpaceLighting/HDRenderPipeline.AmbientOcclusion.cs

@@ -48,8 +48,8 @@ RenderAOParameters PrepareRenderAOParameters(HDCamera camera, Vector2 historySiz
             }
             else
             {
-                parameters.runningRes = new Vector2(camera.actualWidth, camera.actualHeight) * 0.5f;
-                cb._AOBufferSize = new Vector4(camera.actualWidth * 0.5f, camera.actualHeight * 0.5f, 2.0f / camera.actualWidth, 2.0f / camera.actualHeight);
+                parameters.runningRes = new Vector2(Mathf.RoundToInt(camera.actualWidth * 0.5f), Mathf.RoundToInt(camera.actualHeight * 0.5f));
+                cb._AOBufferSize = new Vector4(parameters.runningRes.x, parameters.runningRes.y, 1.0f / parameters.runningRes.x, 1.0f / parameters.runningRes.y);
             }
 
             parameters.temporalAccumulation = settings.temporalAccumulation.value && camera.frameSettings.IsEnabled(FrameSettingsField.MotionVectors);

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

@@ -1296,7 +1296,7 @@ struct AmbientOcclusionAllocator
 
             public RTHandle Allocator(string id, int frameIndex, RTHandleSystem rtHandleSystem)
             {
-                return rtHandleSystem.Alloc(Vector2.one * scaleFactor, TextureXR.slices, filterMode: FilterMode.Point, colorFormat: GraphicsFormat.R32_UInt, dimension: TextureXR.dimension, useDynamicScale: true, enableRandomWrite: true, name: string.Format("{0}_AO Packed history_{1}", id, frameIndex));
+                return rtHandleSystem.Alloc(Vector2.one * scaleFactor, TextureXR.slices, filterMode: FilterMode.Point, colorFormat: GraphicsFormat.R8G8B8A8_UNorm, dimension: TextureXR.dimension, useDynamicScale: true, enableRandomWrite: true, name: string.Format("{0}_AO Packed history_{1}", id, frameIndex));
             }
         }