Vray Hair Material in Max - Tips for best looking renders?

[mitchgates]

We have been doing hair R&D for a project here and up until now rendering using the Hair Farm atmospheric effect. Due to the lack of any ability to use 3d motion blur or proper Vray lights with this approach we have started testing using Vray hair primitive and the VrayHairMtl instead (still using HairFarm for the grooming). The hope is to avoid using any GI if possible and instead rely on and HDR via Vray Domelight plus a few Vray plane lights as needed. However, the initial tests are not looking near as good as the examples here...

http://spot3d.com/vray/images/stuff/hair_tests/

I'm curious if the current VrayHairMtl in Max Vray 2.3 is the same implementation that is called "Hair Material 3" in Maya, or if there are any enhancements in Vray for Maya that improve hair rendering. We would be more than pleased to get anything remotely as nice as this example which is said to use no GI - http://spot3d.com/vray/images/stuff/..._hdr_no_gi.png

If I enable GI and dial up the DMC sampler settings I start to get something halfway nice, but render times are horribly slow by that point. I've been searching around for any in-depth tutorials or info on how the best use the Hair Material but can't find anything beyond the help pages on spot3d. Any advice or example scenes others could point me to would be much appreciated.

Thanks,
Mitch

[vlado]

I'm curious if the current VrayHairMtl in Max Vray 2.3 is the same implementation that is called "Hair Material 3" in Maya

Exactly the same, yes.

We would be more than pleased to get anything remotely as nice as this example which is said to use no GI - http://spot3d.com/vray/images/stuff/..._hdr_no_gi.png

If you are not using GI, you might want to use the diffuse color a bit more instead of the secondary specular/transmission. It will definitely brighten things up a bit.

If I enable GI and dial up the DMC sampler settings I start to get something halfway nice, but render times are horribly slow by that point.

The latest nightly builds include some optimizations in that regard, particularly for transparent hair.

Best regards,
Vlado

[vlado]

Ah, also if all else fails, send me a scene and I'll see what can be done about it.

Best regards,
Vlado

[tammo]

I am back to detailed geometry hair with opacity maps.
Looks good if done right and no more motionblur problems, flickering or long rendertimes.