Fix T87369 EEVEE: Ambient Oclussion: Firefly caused by degenerated normal

This was caused by some sort of degenerated normals.

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/draw/intern/shaders/common_math_lib.glsl b/source/blender/draw/intern/shaders/common_math_lib.glsl
index 378f27056fa..33deae0b0a1 100644
--- a/source/blender/draw/intern/shaders/common_math_lib.glsl
+++ b/source/blender/draw/intern/shaders/common_math_lib.glsl
@@ -91,6 +91,9 @@ vec2 sqr(vec2 a) { return a * a; }
 vec3 sqr(vec3 a) { return a * a; }
 vec4 sqr(vec4 a) { return a * a; }
 
+/* Use manual powers for fixed powers. pow() can have unpredicatble results on some implementations.
+ * (see T87369, T87541) */
+float pow6(float x) { return sqr(sqr(x) * x); }
 float pow8(float x) { return sqr(sqr(sqr(x))); }
 
 float len_squared(vec3 a) { return dot(a, a); }