Blender Cycles OSL: Gold Material

Hi everybody. Today I'm going to show you a migration to OSL of my Gold Material:

In that article I used a mix of colors I called Colombia Gold. Here I have called this mix as Egypt Gold. This is the same node setup in cycles without OSL:

In most of the posts you can find in Blender Artist, the OSL code is used to get a pattern or a texture. This time I have migrated all the nodes information included in that material to the code, trying to minimize the overhead of the node system. So the OSL code is as follows:

/*
*   Migrated from "http://elbrujodelatribu.blogspot.com.es/2013/01/gold-material.html"
*   By: elbrujodelatribu
*/

shader node_metal_gold(
    color ForeColor = 0.8,
    color MiddleColor = 0.4,
    color BackColor = 0.1,
    vector Normal = N,
    float ForeRoughness = 0.01,
    float BackRoughness = 0.04,
    output closure color Metal = 0.0)
{
    closure color ForeClosure = background();
    closure color BackClosure = background();

    // Facing colors - formula from Blender OSL code
    float Factor1 = 1.0 - pow(fabs(dot(I,Normal)),2.0*0.465);
    
    // Dot vectors
    float Factor2 = clamp(pow(dot(Normal,I),1.3),0.0,1.0);

    ForeClosure = ((1-Factor1)*ForeColor + MiddleColor*Factor1)*microfacet_beckmann(Normal,ForeRoughness);
    BackClosure = BackColor*microfacet_beckmann(Normal,BackRoughness);
    
    Metal = ((1-Factor2)*BackClosure)+(ForeClosure*Factor2);
}

And the node setup is this:

And you only need to change the colors for the Colombia Gold:

If you are interested in the render times, in my CPU this material renders 111% longer than the Cycles version without OSL.

Remember you can download these materials for cycles in blendswap.

Bye