From 85c18f1033952f2186432cdb62214501443611ef Mon Sep 17 00:00:00 2001
From: Sam Gateau <sam@highfidelity.io>
Date: Fri, 6 Sep 2019 10:57:54 -0700
Subject: [PATCH] Adding a clamp to 0 to the computed y coordinate while
 unpacking the normal map

---
 libraries/graphics/src/graphics/MaterialTextures.slh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/graphics/src/graphics/MaterialTextures.slh b/libraries/graphics/src/graphics/MaterialTextures.slh
index bf0416c7bf..278057b01a 100644
--- a/libraries/graphics/src/graphics/MaterialTextures.slh
+++ b/libraries/graphics/src/graphics/MaterialTextures.slh
@@ -111,7 +111,7 @@ vec3 fetchNormalMap(vec2 uv) {
     // unpack normal, swizzle to get into hifi tangent space with Y axis pointing out
     vec2 t = 2.0 * (texture(normalMap, uv, TAA_TEXTURE_LOD_BIAS).rg - vec2(0.5, 0.5));
     vec2 t2 = t*t;
-    return vec3(t.x, sqrt(1.0 - t2.x - t2.y), t.y);
+    return vec3(t.x, sqrt(max(0.0, 1.0 - t2.x - t2.y)), t.y);
 }
 <@endif@>