#1852 Fix for some visual corruption caused by divide by zero in lighting functions (#2488)

1 files changed, 7 insertions, 4 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
index ab0e4fd4d8..3319e32cdf 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
@@ -99,10 +99,13 @@ void calcHalfVectors(vec3 lv, vec3 n, vec3 v,
 {
     l  = normalize(lv);
     h  = normalize(l + v);
-    nh = clamp(dot(n, h), 0.0, 1.0);
-    nl = clamp(dot(n, l), 0.0, 1.0);
-    nv = clamp(dot(n, v), 0.0, 1.0);
-    vh = clamp(dot(v, h), 0.0, 1.0);
+
+    // lower bound to avoid divide by zero
+    float eps = 0.000001;
+    nh = clamp(dot(n, h), eps, 1.0);
+    nl = clamp(dot(n, l), eps, 1.0);
+    nv = clamp(dot(n, v), eps, 1.0);
+    vh = clamp(dot(v, h), eps, 1.0);
 
     lightDist = length(lv);
 }