Simple VEX shaders without functions like "get_bsdf"

[fatboYYY]

Hey,

I'm unfortunately already back again with couple of more questions around VEX shaders. I've been trying to write simple VEX shaders, but it got rough as soon as I was trying to create BSDF outputs. As a starting point I wanted to create a chromeball with as few lines as possible. Since you can look up the VEX code from VOP nodes I created the chromeball with as few nodes as possible, looked up their VEX code, took what I needed, and adjusted what I needed to adjust.

This is how the simplest chromeball shader, that I could come up with, looks like:

Quote

#include "bsdf.h"
surface
shop_chrome()
{
    bsdf f;
    f = get_bsdf("ggx", "reflect", normalize(Ng), normalize(N), normalize(I), set(0,0,0), set(0,0,0), set(1,1,1), 0, 0, 0, 0, 1, 0, 0);
    F = f;
}

Unfortunately I had to resort using the get_bsdf function because I could't get the shader to run without it. But since I don't know what is going behind the scenes of that function, I would want to avoid using functions like it.

Are there resources out there where I can look up how to create shader attributes like reflection, refraction, sss, bump, displacement with VEX? Hints at how to use/add up reflection/diffuse bsdfs (or similar stuff) in VEX with example would already help a great amount. 

Thanks again,

fatboY