rendering hair

[oglu]

im playing with vray and hair... but im missing some things... i cant find a the HairInfoTex like in max...
and its seems there is no way to render maya fur... and its still slow to render hair in vray...
are there any plans to get more power for hair rendering...?

[t.petrov]

1. I guess you need the VRayFurSample to replicat HairInfoTex.
2. MayaFur is imposible to render because Autodesk doesn't provide us api, so we don't have access. If you need this go bug them.
3. There are some improvements in regard to hair rendering performance in the works, so stay tuned

[oglu]

thanks for info...
i will bug them...

[vlado]

There is actually a VRayHairInfo utility node in Maya.

Best regards,
Vlado

[vuegroup]

If Autodesk does not supply an api to access fur, how is it that renderman and mental ray are able to render it? I have a job now that I have to take a model set up with maya fur and originally rendered in renderman and I never learnt how to use mental ray, don't have renderman and love using vray but it cant do maya fur. It is somewhat frustrating.
Would it not be possible to make a vray fur node that can be mapped in the same way as the maya fur description, making a conversion possible?
The other issue I have found is with the shave plugin. I tried the demo of shave and rendered it with vray and then tried a version with transparency mapped from the base to the tip where the render time went from 2 minutes to 50 minutes. Shave in their manual explicitly blames vray for poor trancparency performance, and the version with the transparency mapping looks so much better, the fur is soft and fluffy looking, the highlights are softer and it all blends together in a pleasing way. Is there some way to optimise this to be able to use transparency without the 2500% increase in render times?

Thanks

[t.petrov]

If Autodesk does not supply an api to access fur, how is it that renderman and mental ray are able to render it? I have a job now that I have to take a model set up with maya fur and originally rendered in renderman and I never learnt how to use mental ray, don't have renderman and love using vray but it cant do maya fur. It is somewhat frustrating.

I guess there is an API, but it is not public.

Would it not be possible to make a vray fur node that can be mapped in the same way as the maya fur description, making a conversion possible?

No, until we have the full details (specification), what the various attributes do.

[vlado]

If Autodesk does not supply an api to access fur, how is it that renderman and mental ray are able to render it?

Both of them duplicate internally the algorithm used to generate the hair. Since Autodesk does the mental ray connection, obivously this is not a problem. I'm also pretty sure that when Pixar asked them for the algorithm, they were not in position to decline

Would it not be possible to make a vray fur node that can be mapped in the same way as the maya fur description, making a conversion possible?

We don't really have any information about how Maya fur works. It would be a lot of trial and error to try and figure it out and we will still probably miss some cases. With that said, I know that people have successfully written converters for transferring fur textures from Maya fur to V-Ray fur.

Is there some way to optimise this to be able to use transparency without the 2500% increase in render times?

Raytracing of transparent hair is always going to be slow. In any case, we are working to add support for the V-Ray hair shaders for the Shave plugin, which should help with this. They are much better optimized for V-Ray than the built-in Shave shading.

Best regards,
Vlado

[FSGFX]

speeding up hair sounds really good..!