VRayFresnel technical information ?

[cherry0602]

Hi! I have a question regarding the VRayFresnel Shader.

It is nice that this shader allows for direct artistic control of the front specular color and side specular color. But for VRayMtl, it seems these two specular colors are decided by the IOR only, maybe by Schlick's approximation? I am really curious about how the VRrayFresnel shader handles the parameters Front Color, Side Color, and IOR internally.

Is there anywhere that I can find more technical information about this shader?

Many thanks!

[vlado]

The sources for the Fresnel texture are included in the V-Ray SDK which comes with every installation of V-Ray for Maya (f.e. in C:\Program Files\Chaos Group\V-Ray\Maya 2014 for x64\samples\vray_plugins\textures\vray_texfresnel) . It should be enough to answer any questions that you have about it, but if something is still not clear, please post again.

Best regards,
Vlado

[cherry0602]

Vlado, thank you very much for the information!

I read the source code of the sample texture shader, vray_texfresnel, briefly. I didn't get to try compiling this shader and compare it with the released one yet. Is this one a bit different? It seems like this one defines two IOR input parameters, fresnel_ior and refract_ior, while the released one has just one ior parameter...

Thank you!

[cherry0602]

Hello again. I'm sorry for my previous stupid question. I found the desc.txt file; fresnel_ior and refract_ior are both mapped to the input parameter IOR.

[vlado]

Yes, I was going to say that; by default they are mapped to the same value. This is needed for determining what happens with total internal reflections for glass materials.

Best regards,
Vlado