Merge pull request #14752 from greggman/non-overflowing-fog

Make distance fog calculation overflow less in mediump
mrdoob · Aug 21, 2018 · 508b82d · 508b82d
2 parents 4ab0e69 + 33f69d7
commit 508b82d
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/renderers/shaders/ShaderChunk/fog_fragment.glsl b/src/renderers/shaders/ShaderChunk/fog_fragment.glsl
@@ -1,6 +1,9 @@
 #ifdef USE_FOG
 
-	float fogDepth = length( vFogPosition );
+	// divide then multiply by max component to try to avoid saturating mediump precision
+	vec3 fogPositionAbs = abs( vFogPosition );
+	float fogMaxComponent = max( fogPositionAbs.x, max( fogPositionAbs.y, fogPositionAbs.z ) );
+	float fogDepth = length( vFogPosition / fogMaxComponent ) * fogMaxComponent;
 
 	#ifdef FOG_EXP2