Fix Resolution Issues for Physically Based Depth of Field

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

@@ -246,6 +246,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed the transparent cutoff not working properly in semi-transparent and color shadows (case 1340234).
 - Fixed object outline flickering with TAA.
 - Fixed issue with sky settings being ignored when using the recorder and path tracing (case 1340507).
+- Fixed some resolution aliasing for physically based depth of field (case 1340551).
+- Fixed an issue with resolution dependence for physically based depth of field.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard

com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/DoFGather.compute

@@ -34,11 +34,10 @@ RW_TEXTURE2D_X(CTYPE, _OutputTexture);
 // A set of Defines to fine-tune the algorithm
 #define ADAPTIVE_SAMPLING
 #define STRATIFY
-#define FORCE_POINT_SAMPLING
 #define RING_OCCLUSION
 #define PER_TILE_BG_FG_CLASSIFICATION
 #define PHYSICAL_WEIGHTS
-
+#define FORCE_POINT_SAMPLING
 
 #define GROUP_RES  8u
 #define GROUP_SIZE (GROUP_RES * GROUP_RES)
@@ -73,9 +72,16 @@ float GetCoCRadius(int2 positionSS)
 CTYPE GetColorSample(float2 sampleTC, float lod)
 {
 #ifndef FORCE_POINT_SAMPLING
-    return SAMPLE_TEXTURE2D_X_LOD(_InputTexture, s_trilinear_clamp_sampler, ClampAndScaleUVForBilinearPostProcessTexture(sampleTC * _PostProcessScreenSize.zw), lod).CTYPE_SWIZZLE;
+    float texelsToClamp = (1u << (uint)ceil(lod)) + 1;
+    float2 uv = ClampAndScaleUVPostProcessTexture(sampleTC * _PostProcessScreenSize.zw, _PostProcessScreenSize.zw, texelsToClamp);
+
+    // Trilinear sampling can introduce some "leaking" between in-focus and out-of-focus regions, hence why we force point
+    // sampling. Ideally, this choice should be per-tile (use trilinear only in tiles without in-focus pixels), but until
+    // we do this, it is more safe to point sample.
+    return SAMPLE_TEXTURE2D_X_LOD(_InputTexture, s_trilinear_clamp_sampler, uv, lod).CTYPE_SWIZZLE;
 #else
-    return LOAD_TEXTURE2D_X(_InputTexture, sampleTC).CTYPE_SWIZZLE;
+    float2 uv = ClampAndScaleUVPostProcessTextureForPoint(sampleTC * _PostProcessScreenSize.zw);
+    return SAMPLE_TEXTURE2D_X_LOD(_InputTexture, s_point_clamp_sampler, uv, 0.0).CTYPE_SWIZZLE;
 #endif
 }
 

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

@@ -2413,14 +2413,19 @@ static void ReprojectCoCHistory(in DepthOfFieldParameters parameters, CommandBuf
 
         static void DoPhysicallyBasedDepthOfField(in DepthOfFieldParameters dofParameters, CommandBuffer cmd, RTHandle source, RTHandle destination, RTHandle fullresCoC, RTHandle prevCoCHistory, RTHandle nextCoCHistory, RTHandle motionVecTexture, RTHandle sourcePyramid, RTHandle depthBuffer, RTHandle minMaxCoCPing, RTHandle minMaxCoCPong, bool taaEnabled)
         {
-            float scale = 1f / (float)dofParameters.resolution;
-            int targetWidth = Mathf.RoundToInt(dofParameters.viewportSize.x * scale);
-            int targetHeight = Mathf.RoundToInt(dofParameters.viewportSize.y * scale);
+            // Currently Physically Based DoF is performed at "full" resolution (ie does not utilize DepthOfFieldResolution)
+            // However, to produce similar results when switching between various resolutions, or dynamic resolution,
+            // we must incorporate resolution independence, fitted with a 1920x1080 reference resolution.
+            var scale = dofParameters.viewportSize / new Vector2(1920f, 1080f);
+            float resolutionScale = Mathf.Min(scale.x, scale.y) * 2f;
+
+            float farMaxBlur  = resolutionScale * dofParameters.farMaxBlur;
+            float nearMaxBlur = resolutionScale * dofParameters.nearMaxBlur;
 
             // Map the old "max radius" parameters to a bigger range, so we can work on more challenging scenes, [0, 16] --> [0, 64]
             Vector2 cocLimit = new Vector2(
-                Mathf.Max(4 * dofParameters.farMaxBlur, 0.01f),
-                Mathf.Max(4 * dofParameters.nearMaxBlur, 0.01f));
+                Mathf.Max(4 * farMaxBlur, 0.01f),
+                Mathf.Max(4 * nearMaxBlur, 0.01f));
             float maxCoc = Mathf.Max(cocLimit.x, cocLimit.y);
 
             ComputeShader cs;