Tips for rendering XGen hair?

[leabum]

I am rendering a human character with lots of very fine hair. I created a renderlayer for the hair only, where I assigned object properties to all the other meshes as a matte surface with -1 alpha to only render whats visible. That way I can just overlay it in nuke. Makes sense?
Anyways. What are common settings for rendering hair. I am getting very close to the character face and then the camera is zooming out. My AA threshold is set to 0.015 and Max subdivs to only 10 (Gauss 1.5). The sample rate AOV is red almost everywhere. Making the AA threshold a lot higher still gives me a very red sample rate. Vray seems to want to sample it very high. I means it hair from a very low distance so I think thats okay right? Eventhough Max Subdivs are just set to 10 it is rendering very long. With distributed rendering on 4 machines and an already existing GI prepass I am at about an hour. Is that okay or way too long. Going lower that 10 will definitely give me flickering.

Are those values way off, what are common setting for efficient hair rendering.

[svetlozar.draganov]

Rendering hair or other fine primitives usually requires a lot more Max Sibdivs something, values between 24 and 50 are typical values for such scenes.
10 Subdivsions are usually not enough to generate a smooth animation but like always everything depends from the scene that's why there aren't a universal settings.

Render time depends from from the quality expectations, if you can afford lower quality image/animation you may decrease IS settings that would give you a better render times, if that's not possible however an hour per frame is what you need to pay for those frames.

Can you show us a sample of the final render in full resolution so we could get a better idea how it looks like.

[leabum]

https://www.youtube.com/watch?v=kblu...ature=youtu.be

Here you can see a first render. There is obviousely a problem with the fur in the nosearea, which is not related to the AA samples I guess. Probably one of many XGen Bugs.
But in general I think it is somewhat okay. I will most likely go a bit higher though.

[svetlozar.draganov]

The video from the shared link is private.

[leabum]

sorry! fixed it