Cook Torrance Shader

[l.a. akira]

I know there has been some talk about this in the past but one thing I would really like this for is lighting pearlescent paints in direct sunlight properly. When a job calls for a silver car nowadays, it comes down to separate passes in nuke and even still, some angles just don't look the way they should.

It pains me to think theres something lightwave has that Vray doesnt. :P

[vlado]

The problem with the Cook-Torrance shader is that there is no good way to sample the reflections (well, at least not as efficient as Blinn/Phong/Ward). In any case, I've logged it as a wish, so it may appear at one point.

Best regards,
Vlado

[l.a. akira]

Even if its not physically accurate, thats fine with me just as long as it can mimic the falloff behavior in high contrast lighting environments such as direct sunlight and night shots with many little hotspots like street lights, etc. I'm not so worried about getting stills looking good as much as I am animations. When the client asks for a silver car (which has been happening quite a bit these days) and wants some crazy camera move, I'm sure you can imagine how the hack methods for getting a good "look" for the metallics might fall apart.

[Morbid Angel]

I second this, and also a velvet shader would be great.

[anchovy]

I wrote the velvet shader for Brazil but havent delved into the sdk for Vray yet. I am wondering if there is a plugin system so an arbitrary luminance model can be plugged into the vray mtl. I doubt it but its a lot more work than just defining the illumination loop to have a mtl that does everything the vray mtl does. That being said Id love to see Cook Torrance and Oren Nayar. Both are very useful.

-Michael

[vlado]

There is not a direct way to plug a new model to the VRayMtl material, but it is perfectly possible to write a separate BRDF shader and use VRayBlendMtl to combine it with other shaders. There is an example for this in the SDK called VRayBlinnMtl.

Best regards,
Vlado