Fix motion blur compute dispatch size (#4737)

adrien-de-tocqueville · sebastienlagarde · web-flow · commit 419850bcca1c · 2021-06-08T00:19:42.000+02:00
Co-authored-by: sebastienlagarde &lt;sebastien@unity3d.com&gt;
diff --git a/com.unity.render-pipelines.high-definition/CHANGELOG.md b/com.unity.render-pipelines.high-definition/CHANGELOG.md
@@ -234,6 +234,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed reflection probes being injected into the ray tracing light cluster even if not baked (case 1329083).
 - Fixed the double sided option moving when toggling it in the material UI (case 1328877).
 - Fixed volumetric fog in planar reflections.
+- Fixed error with motion blur and small render targets.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard
diff --git a/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/HDRenderPipeline.PostProcess.cs b/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/HDRenderPipeline.PostProcess.cs
@@ -2953,8 +2953,8 @@ void PrepareMotionBlurPassData(RenderGraph renderGraph, in RenderGraphBuilder bu
                 tileSize = 16;
             }
 
-            int tileTexWidth = Mathf.CeilToInt(postProcessViewportSize.x / tileSize);
-            int tileTexHeight = Mathf.CeilToInt(postProcessViewportSize.y / tileSize);
+            int tileTexWidth = Mathf.CeilToInt(postProcessViewportSize.x / (float)tileSize);
+            int tileTexHeight = Mathf.CeilToInt(postProcessViewportSize.y / (float)tileSize);
             data.tileTargetSize = new Vector4(tileTexWidth, tileTexHeight, 1.0f / tileTexWidth, 1.0f / tileTexHeight);
 
             float screenMagnitude = (new Vector2(postProcessViewportSize.x, postProcessViewportSize.y).magnitude);

Original file line number	Diff line number	Diff line change
`@@ -2953,8 +2953,8 @@ void PrepareMotionBlurPassData(RenderGraph renderGraph, in RenderGraphBuilder bu`
`2953`	`2953`	`tileSize = 16;`
`2954`	`2954`	`}`
`2955`	`2955`
`2956`		`- int tileTexWidth = Mathf.CeilToInt(postProcessViewportSize.x / tileSize);`
`2957`		`- int tileTexHeight = Mathf.CeilToInt(postProcessViewportSize.y / tileSize);`
	`2956`	`+ int tileTexWidth = Mathf.CeilToInt(postProcessViewportSize.x / (float)tileSize);`
	`2957`	`+ int tileTexHeight = Mathf.CeilToInt(postProcessViewportSize.y / (float)tileSize);`
`2958`	`2958`	`data.tileTargetSize = new Vector4(tileTexWidth, tileTexHeight, 1.0f / tileTexWidth, 1.0f / tileTexHeight);`
`2959`	`2959`
`2960`	`2960`	`float screenMagnitude = (new Vector2(postProcessViewportSize.x, postProcessViewportSize.y).magnitude);`