To expand vray you can write custom shaders using the excisting SDK.
Well i had a go at it.
I first got into the 3dsmax SDK and tried to create a couple or plugins (simple ones like a custom object, simple 2D proc texture)
Now with the Vray SDK i have a hard time understanding the examples and writing custom/new shader.
You can download loads of shader for other renders and try to get them working with vray (so you do not have tu realy understand the underlying math and such ).
This i not that easy.
So i’m wondering if you c++ gods have some time left to describe the starting up for custom shaders. in my humble opinion this will greatly increase vray’s materials/shader section if more people would write shaders.
In the SDK, there is the source code of a simple Blinn shader for V-Ray - you can easily modify this to suit your needs.
Basically, for any shader, V-Ray would require that you can calculate two things:
1) given a viewing direction and a light ray, the amount of light transmitted from the light ray to the viewer;
2) given some random numbers on the unit square, how to transform them into a direction for tracing reflections, and the probability for generating that direction.
).