From 6e7d31277c199366cb2c2de2518b8eea91611d02 Mon Sep 17 00:00:00 2001
From: James Baicoianu <james_github@baicoianu.com>
Date: Wed, 23 Nov 2016 21:37:25 -0800
Subject: [PATCH] Added logarithmic depth buffer support to SSAO postprocessing
 shader

---
 examples/js/shaders/SSAOShader.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/examples/js/shaders/SSAOShader.js b/examples/js/shaders/SSAOShader.js
index b086c1ec91..c786f6075b 100644
--- a/examples/js/shaders/SSAOShader.js
+++ b/examples/js/shaders/SSAOShader.js
@@ -44,6 +44,9 @@ THREE.SSAOShader = {
 
 		"uniform float cameraNear;",
 		"uniform float cameraFar;",
+		"#ifdef USE_LOGDEPTHBUF",
+			"uniform float logDepthBufFC;",
+		"#endif",
 
 		"uniform bool onlyAO;",      // use only ambient occlusion pass?
 
@@ -109,8 +112,19 @@ THREE.SSAOShader = {
 			"float cameraFarMinusNear = cameraFar - cameraNear;",
 			"float cameraCoef = 2.0 * cameraNear;",
 
-			// "return ( 2.0 * cameraNear ) / ( cameraFar + cameraNear - unpackDepth( texture2D( tDepth, coord ) ) * ( cameraFar - cameraNear ) );",
-			"return cameraCoef / ( cameraFarPlusNear - unpackRGBAToDepth( texture2D( tDepth, coord ) ) * cameraFarMinusNear );",
+			"#ifdef USE_LOGDEPTHBUF",
+
+				"float logz = unpackRGBAToDepth( texture2D( tDepth, coord ) );",
+				"float w = pow(2.0, (logz / logDepthBufFC)) - 1.0;",
+				"float z = (logz / w) + 1.0;",
+
+			"#else",
+
+				"float z = unpackRGBAToDepth( texture2D( tDepth, coord ) );",
+
+			"#endif",
+
+			"return cameraCoef / ( cameraFarPlusNear - z * cameraFarMinusNear );",
 
 
 		"}",
-- 
GitLab