Maya Hair Render Time

[Zach Gray]

The following 1:1 image took over 8 minutes.



Dome and two area lights, all with 8 subdivs.
Very low irradiance map. Adaptive subdiv -1 2.
Hair IS transparent.

8 core with 12GB ram, dynamic memory 6gb

Approx 1300 hairs.

Seems too long. If this IS correct, how can I optimize for preview?

[vlado]

Which build are you using? There are some optimizations in that regard in the latest night builds, and more are coming. There was a slow-down particularly with long hairs with many knots.

Best regards,
Vlado

[Zach Gray]

Build 12435. I requested access to nightly builds earlier, but nothing happened. I'd be happy to try those.

[vlado]

Hm, I can't find an email from you... did you send it to vlado@chaosgroup.com?

Best regards,
Vlado

[aweidenhammer]

I've noticed transparency is a huge hit to rendertimes. In one hires still, I shut off transparency, and used a few offset layers of the hair at different opacity levels to imitate it in photoshop. This is certainly not a solution, but when I'm rendering 7 or 8k, it was the only solution for me I didn't know about the many-knots issue though. I'm glad to see that was worked on.

[Zach Gray]

Sent originally 10/14/2010, followed up on 1/13/2011. From zcgray at southern . edu

[vlado]

Yep, check your email.

Best regards,
Vlado

[Zach Gray]

Seems to have helped a little, but I'm only getting 12% on cpu, a single core at most of the time. Is the process multithreaded or can I assign more CPUs to different buckets in a setting somewhere?

Thank you.

[vlado]

Hm, this is odd then. If you can get me a scene to vlado@chaosgroup.com for investigation, it will be very helpful.

Best regards,
Vlado

[ceql]

Which build are you using? There are some optimizations in that regard in the latest night builds, and more are coming. There was a slow-down particularly with long hairs with many knots.

Best regards,
Vlado

!!! Interesting! I'm doing some long hair stuff at the momment (e.g http://www.images.crayongrind.com/im...S!!05_crop.jpg ) and I could use as much speed boost as possible! Any chance I could get on the latest builds too? I'll send an email.... (from carloslin @ gmail.com)

[Zach Gray]

I saw some improvement in the render, but they absolutely tanked when I turned on transparency. Unfortunately, I couldn't get a nice soft look without transparency, so I had to resort to a surface shader with a facing ratio falloff. Definitely not as sophisticated as a real hair, but it was soft.