shave and render passes

[vlado]

@matus.nedecky

I do know that the passes themselves work with shave. For example you can generate a spec pass that will work on the shave hair along with everything else. Occlusion is a big problem though because it takes (understandably) a really long time to render occlusion on hair. So simply having render passes on a scene with shave hair is problematic since it will take a huge hit on render times. So it there a way to exclude the hair from the occlusion calculation in the extra-tex pass?

Hm, while you can exclude objects from occlusion in the V-Ray dirt texture, the shave geometry is created at render time, so there is no way to link it to the dirt texture. You might be able to do this from the post-translate Python callback. However I’m somewhat doubtful that it will speed things up - the hair would be still in the scene, and it will still need to be processed for any rays that pass through it. I’m afraid in that case it would be best to compute the occlusion in a separate render without the hair.

Last time I checked there was not a way to get the hair into multi-matte because there was no way to assign the shave hair and object ID. Has this changed in 2.0? Would there be a way to set it up with a material ID? That would not work with the native Shave shader, but maybe we could assign a vray hair shader to it?You could be able to do it from said post-translate Python callback - you will need to set the “objectID” of the shave Node object in the V-Ray scene.

Best regards,
Vlado