Fix terrain holes rendering on Quest4 and Pico2 - UUM 61913

LilithDuncanUnity · Evergreen · commit edb595e98b0a · 2024-05-11T02:34:07.000Z
Fixes a bug with terrain rendering on Quest2/Pico4 where holes would not display properly. [UUM-61913](https://jira.unity3d.com/browse/UUM-61913)
diff --git a/Packages/com.unity.render-pipelines.universal/Shaders/Terrain/TerrainLitInput.hlsl b/Packages/com.unity.render-pipelines.universal/Shaders/Terrain/TerrainLitInput.hlsl
@@ -93,7 +93,9 @@ SAMPLER(sampler_TerrainHolesTexture);
 void ClipHoles(float2 uv)
 {
     float hole = SAMPLE_TEXTURE2D(_TerrainHolesTexture, sampler_TerrainHolesTexture, uv).r;
-    clip(hole == 0.0f ? -1 : 1);
+    // Fixes bug where compression is enabled and 0 isn't actually 0 but low like 1/2047. (UUM-61913)
+    float epsilon = 0.0005f;
+    clip(hole < epsilon ? -1 : 1);
 }
 #endif
 

Original file line number	Diff line number	Diff line change
`@@ -93,7 +93,9 @@ SAMPLER(sampler_TerrainHolesTexture);`
`93`	`93`	`void ClipHoles(float2 uv)`
`94`	`94`	`{`
`95`	`95`	`float hole = SAMPLE_TEXTURE2D(_TerrainHolesTexture, sampler_TerrainHolesTexture, uv).r;`
`96`		`- clip(hole == 0.0f ? -1 : 1);`
	`96`	`+ // Fixes bug where compression is enabled and 0 isn't actually 0 but low like 1/2047. (UUM-61913)`
	`97`	`+ float epsilon = 0.0005f;`
	`98`	`+ clip(hole < epsilon ? -1 : 1);`
`97`	`99`	`}`
`98`	`100`	`#endif`
`99`	`101`