Register aliasable UAV resources globally, before and after scheduling shader dispatches, so that all compute shaders can make use of them but without requiring a whole lot of additional resource management code.

Assets/Scripts/Fsr2Context.cs

@@ -184,6 +184,8 @@ namespace FidelityFX
             _fsr2ConstantsBuffer.SetData(_fsr2ConstantsArray);
             _spdConstantsBuffer.SetData(_spdConstantsArray);
             
+            Fsr2Pipeline.RegisterResources(_commandBuffer, dispatchParams);
+            
             // Compute luminance pyramid
             _computeLuminancePyramidPipeline.ScheduleDispatch(_commandBuffer, dispatchParams, dispatchThreadGroupCount.x, dispatchThreadGroupCount.y);
 
@@ -224,7 +226,7 @@ namespace FidelityFX
 
             Graphics.ExecuteCommandBuffer(_commandBuffer);
             
-            // TODO Unregister resources: release temp RT's
+            Fsr2Pipeline.UnregisterResources(_commandBuffer);
         }
 
         private void SetupConstants(Fsr2.DispatchDescription dispatchParams, bool resetAccumulation)

Assets/Scripts/Fsr2Pipeline.cs

@@ -45,8 +45,29 @@ namespace FidelityFX
         {
             UnloadComputeShader();
         }
-        
+
         public abstract void ScheduleDispatch(CommandBuffer commandBuffer, Fsr2.DispatchDescription dispatchParams, int dispatchX, int dispatchY);
+
+        public static void RegisterResources(CommandBuffer commandBuffer, Fsr2.DispatchDescription dispatchParams)
+        {
+            // Set up shared aliasable resources, i.e. temporary render textures
+            // These do not need to persist between frames, but they do need to be available between compute stages
+            
+            // Resource FSR2_SpdAtomicCounter: FFX_RESOURCE_USAGE_UAV, FFX_SURFACE_FORMAT_R32_UINT, FFX_RESOURCE_FLAGS_ALIASABLE
+            commandBuffer.GetTemporaryRT(UavSpdAtomicCount, 1, 1, 0, FilterMode.Point, GraphicsFormat.R32_UInt, 1, true);
+            
+            // Resource FSR2_ExposureMips: FFX_RESOURCE_USAGE_UAV, FFX_SURFACE_FORMAT_R16_FLOAT, FFX_RESOURCE_FLAGS_ALIASABLE, has mipmap chain
+            commandBuffer.GetTemporaryRT(UavExposureMipLumaChange, dispatchParams.RenderSize.x >> 4, dispatchParams.RenderSize.y >> 4, 0, FilterMode.Point, GraphicsFormat.R16_SFloat, 1, true);
+            commandBuffer.GetTemporaryRT(UavExposureMip5, dispatchParams.RenderSize.x >> 5, dispatchParams.RenderSize.y >> 5, 0, FilterMode.Point, GraphicsFormat.R16_SFloat, 1, true);
+        }
+
+        public static void UnregisterResources(CommandBuffer commandBuffer)
+        {
+            // Release all of the aliasable resources used this frame
+            commandBuffer.ReleaseTemporaryRT(UavSpdAtomicCount);
+            commandBuffer.ReleaseTemporaryRT(UavExposureMipLumaChange);
+            commandBuffer.ReleaseTemporaryRT(UavExposureMip5);
+        }
         
         protected void LoadComputeShader(string name, Fsr2.InitializationFlags flags)
         {
@@ -109,24 +130,11 @@ namespace FidelityFX
             // - Shouldn't we use a ComputeBuffer for resources that are one-dimensional and clearly not image data? e.g. SPD atomic counter & Lanczos LUT data
 
             commandBuffer.SetComputeTextureParam(ComputeShader, KernelIndex, SrvInputColor, dispatchParams.Input);
-            // Resource FSR2_SpdAtomicCounter: FFX_RESOURCE_USAGE_UAV, FFX_SURFACE_FORMAT_R32_UINT, FFX_RESOURCE_FLAGS_ALIASABLE
-            commandBuffer.GetTemporaryRT(UavSpdAtomicCount, 1, 1, 0, FilterMode.Point, GraphicsFormat.R32_UInt, 1, true);   // FSR2_BIND_UAV_SPD_GLOBAL_ATOMIC
-            // Resource FSR2_ExposureMips: FFX_RESOURCE_USAGE_UAV, FFX_SURFACE_FORMAT_R16_FLOAT, FFX_RESOURCE_FLAGS_ALIASABLE, mipCount = 0
-            // See `scheduleDispatch` for the song and dance to bind UAV mip levels to each luminance mipmap... and this shader specifically wants mip levels 4 and 5
-            // Looks like we can just bind two separate resources here, shouldn't be necessary to bother with mipmapping nonsense. Be sure to get the right dimensions though.
-            commandBuffer.GetTemporaryRT(UavExposureMipLumaChange, dispatchParams.RenderSize.x >> 4, dispatchParams.RenderSize.y >> 4, 0, FilterMode.Point, GraphicsFormat.R16_SFloat, 1, true);    // FSR2_BIND_UAV_EXPOSURE_MIP_LUMA_CHANGE
-            commandBuffer.GetTemporaryRT(UavExposureMip5, dispatchParams.RenderSize.x >> 5, dispatchParams.RenderSize.y >> 5, 0, FilterMode.Point, GraphicsFormat.R16_SFloat, 1, true);    // FSR2_BIND_UAV_EXPOSURE_MIP_5
-            commandBuffer.SetComputeTextureParam(ComputeShader, KernelIndex, UavAutoExposure, _autoExposure);   // FSR2_BIND_UAV_AUTO_EXPOSURE
+            commandBuffer.SetComputeTextureParam(ComputeShader, KernelIndex, UavAutoExposure, _autoExposure);
             commandBuffer.SetComputeConstantBufferParam(ComputeShader, CbFsr2, Constants, 0, Marshal.SizeOf<Fsr2.Fsr2Constants>());
             commandBuffer.SetComputeConstantBufferParam(ComputeShader, CbSpd, _spdConstants, 0, Marshal.SizeOf<Fsr2.SpdConstants>());
             
             commandBuffer.DispatchCompute(ComputeShader, KernelIndex, dispatchX, dispatchY, 1);
-            
-            // NOTE: since these temp RTs are not bound to a specific shader or kernel, we can set them globally one time and release them after dispatch.
-            // That way we can share aliasable resources between shaders without any complicated management. 
-            commandBuffer.ReleaseTemporaryRT(UavSpdAtomicCount);
-            commandBuffer.ReleaseTemporaryRT(UavExposureMipLumaChange);
-            commandBuffer.ReleaseTemporaryRT(UavExposureMip5);
         }
     }