From 8dc267984d9b85a64e40d25ab1cc3ffd531d4d2b Mon Sep 17 00:00:00 2001
From: Mike Daum <mike.daum@coobeeyon.net>
Date: Fri, 3 Apr 2026 16:15:46 -0400
Subject: [PATCH] Fix HALFRES compositer darkening background behind
 transparent geometry
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The HALFRES code path in the EffectCompositer hardcodes
vec4(0.0, 0.0, 0.0, 1.0) for far-plane pixels (depth == 1.0). The R
channel (0.0) is interpreted as full ambient occlusion, which darkens
the entire background when transparent objects with depthWrite disabled
leave far-plane depth values in the depth buffer.

Replace the hardcoded constant with texture2D(tDiffuse, vUv), which
bilinearly samples the AO buffer. For background pixels the AO pass
already writes 1.0 (no occlusion), so the result is correct while also
providing smooth edge transitions at geometry boundaries — avoiding the
visible halo that a hard constant produces.
---
 src/EffectCompositer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/EffectCompositer.js b/src/EffectCompositer.js
index 3ac8c77..33195fb 100644
--- a/src/EffectCompositer.js
+++ b/src/EffectCompositer.js
@@ -177,7 +177,7 @@ const EffectCompositer = {
         #ifdef HALFRES 
         vec4 texel;
         if (depth == 1.0) {
-            texel = vec4(0.0, 0.0, 0.0, 1.0);
+            texel = texture2D(tDiffuse, vUv);
         } else {
         vec3 worldPos = getWorldPos(depth, vUv);
         vec3 normal = computeNormal(getWorldPos(depth, vUv), vUv);