optimize Shadow RT load on Tile based architecture platforms. (#4791)

victor-unity · sebastienlagarde · commit b5e9a57bcd1a · 2019-10-11T17:35:35.000+02:00
* optimize Shadow RT load on Tile based architecture platforms.

RenderBufferLoadAction Load is expensive as it keeps the RT in tile.

* Update CHANGELOG.md
diff --git a/com.unity.render-pipelines.high-definition/CHANGELOG.md b/com.unity.render-pipelines.high-definition/CHANGELOG.md
@@ -90,6 +90,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Disable Physically Based Sky below ground
 - Increase max limit of area light and reflection probe to 128
 - Change default texture for detailmap to grey
+- Optimize Shadow RT load on Tile based architecture platforms. 
 
 ## [7.1.1] - 2019-09-05
 
diff --git a/com.unity.render-pipelines.high-definition/Runtime/Lighting/Shadow/HDShadowAtlas.cs b/com.unity.render-pipelines.high-definition/Runtime/Lighting/Shadow/HDShadowAtlas.cs
@@ -506,7 +506,7 @@ static void RenderShadows(  RenderShadowsParameters parameters,
                                     ScriptableRenderContext renderContext,
                                     CommandBuffer           cmd)
         {
-            cmd.SetRenderTarget(atlasRenderTexture);
+            cmd.SetRenderTarget(atlasRenderTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store);
             cmd.SetGlobalVector(parameters.atlasSizeShaderID, new Vector4(atlasRenderTexture.rt.width, atlasRenderTexture.rt.height, 1.0f / atlasRenderTexture.rt.width, 1.0f / atlasRenderTexture.rt.height));
 
             // Clear the whole atlas to avoid garbage outside of current request when viewing it.

Original file line number	Diff line number	Diff line change
`@@ -506,7 +506,7 @@ static void RenderShadows( RenderShadowsParameters parameters,`
`506`	`506`	`ScriptableRenderContext renderContext,`
`507`	`507`	`CommandBuffer cmd)`
`508`	`508`	`{`
`509`		`- cmd.SetRenderTarget(atlasRenderTexture);`
	`509`	`+ cmd.SetRenderTarget(atlasRenderTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store);`
`510`	`510`	`cmd.SetGlobalVector(parameters.atlasSizeShaderID, new Vector4(atlasRenderTexture.rt.width, atlasRenderTexture.rt.height, 1.0f / atlasRenderTexture.rt.width, 1.0f / atlasRenderTexture.rt.height));`
`511`	`511`
`512`	`512`	`// Clear the whole atlas to avoid garbage outside of current request when viewing it.`