X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=shaderlib%2Fcooktorrance.glsl;h=02d697b087c640572a2ed0ebad15fe655ff4f1d2;hb=8bf70f4d445cf63386ad7aafc5b3ebdbd8369939;hp=33035ee3fa03a0b5b703ef692e710baeac336f5f;hpb=a3c33df71e507380100069ad7ef802b61de351bb;p=libs%2Fgl.git

diff --git a/shaderlib/cooktorrance.glsl b/shaderlib/cooktorrance.glsl
index 33035ee3..02d697b0 100644
--- a/shaderlib/cooktorrance.glsl
+++ b/shaderlib/cooktorrance.glsl
@@ -86,7 +86,8 @@ float normal_distribution_ggxtr(vec3 normal, vec3 halfway, float roughness)
 	float rough_q = roughness * roughness;
 	rough_q *= rough_q;
 	float denom = n_dot_h*n_dot_h*(rough_q-1)+1;
-	// Scale by pi to get a result per steradian, suitable for integration
+	/* Scale by pi to normalize the total area of the microfacets as projected
+	to the macrosurface */
 	return rough_q/(PI*denom*denom);
 }
 
@@ -113,7 +114,7 @@ vec3 fresnel_schlick(vec3 halfway, vec3 look, vec3 base_color, float metalness)
 {
 	// 0.04 is a decent approximation for dielectric base reflectivity
 	vec3 f0 = mix(vec3(0.04), base_color, metalness);
-	return mix(f0, vec3(1.0), pow(1.0-dot(halfway, look), 5.0));
+	return mix(f0, vec3(1.0), pow(max(1.0-dot(halfway, look), 0.0), 5.0));
 }
 
 /* Computes the full contribution of a single light */