[Bf-blender-cvs] [886ea375723] blender2.8: Fix T51979: Eevee: Bloom artifacts w/ zero area faces

[Campbell Barton]

Commit: 886ea375723df23a219af38688fbad4b7766fb3a
Author: Campbell Barton
Date:   Fri Jul 14 15:27:08 2017 +1000
Branches: blender2.8
https://developer.blender.org/rB886ea375723df23a219af38688fbad4b7766fb3a

Fix T51979: Eevee: Bloom artifacts w/ zero area faces

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M	source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl

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diff --git a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
index c8fd57412ef..1cfc00ef8d7 100644
--- a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
@@ -26,11 +26,23 @@ in vec3 viewNormal;
 
 vec3 eevee_surface_lit(vec3 N, vec3 albedo, vec3 f0, float roughness, float ao)
 {
+	/* Zero length vectors cause issues, see: T51979. */
+#if 0
+	N = normalize(N);
+#else
+	{
+		float len = length(N);
+		if (isnan(len)) {
+			return vec3(0.0);
+		}
+		N /= len;
+	}
+#endif
+
 	roughness = clamp(roughness, 1e-8, 0.9999);
 	float roughnessSquared = roughness * roughness;
 
 	vec3 V = cameraVec;
-	N = normalize(N);
 
 	vec4 rand = texture(utilTex, vec3(gl_FragCoord.xy / LUT_SIZE, 2.0));