Improve orthographic projected depth precision in logdepthbuf mode

gl_FragCoord.z is imprecise on some platforms, so this should write out a more precise depth value.
mrdoob · Feb 24, 2020 · 11a92d0 · 11a92d0
1 parent fb7edb9
commit 11a92d0
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Showing 2 changed files with 6 additions and 3 deletions.
diff --git a/src/renderers/shaders/ShaderChunk/logdepthbuf_fragment.glsl.js b/src/renderers/shaders/ShaderChunk/logdepthbuf_fragment.glsl.js
@@ -3,7 +3,7 @@ export default /* glsl */`
 
 	// Doing a strict comparison with == 1.0 can cause noise artifacts
 	// on some platforms. See issue #17623.
-	gl_FragDepthEXT = vIsPerspective == 0.0 ? gl_FragCoord.z : log2( vFragDepth ) * logDepthBufFC * 0.5;
+	gl_FragDepthEXT = vIsPerspective == 0.0 ? vFragDepth : log2( vFragDepth ) * logDepthBufFC * 0.5;
 
 #endif
 `;
diff --git a/src/renderers/shaders/ShaderChunk/logdepthbuf_vertex.glsl.js b/src/renderers/shaders/ShaderChunk/logdepthbuf_vertex.glsl.js
@@ -3,8 +3,11 @@ export default /* glsl */`
 
 	#ifdef USE_LOGDEPTHBUF_EXT
 
-		vFragDepth = 1.0 + gl_Position.w;
-		vIsPerspective = float( isPerspectiveMatrix( projectionMatrix ) );
+		bool isPerspective = isPerspectiveMatrix( projectionMatrix );
+
+		vIsPerspective = float( isPerspective );
+
+		vFragDepth = isPerspective ? 1.0 + gl_Position.w : gl_Position.z * 0.5 + 0.5;
 
 	#else