Flickering in shadows with Global Illumination

[ecarlsen]

Hi, this may be a common issue, but I've been experiencing lots of flickering in the shadows of my renders with global illumination enabled. I'm using Maya 2017/2018 and V-Ray 3.0.

As a first attempt to fix this, in the GI tab, under Light Cache, I increased subdivs from 1000 to 2000, and decreased sample size from .010 to .001. I think it improved the situation, but it's still present in small tight areas. What should my next move be? Further increase the light cache subdivs? Increase the min/max subdivs in the main VRay tab?

I've included images of my VRay and GI tab settings. Note that I've got it set to max render of 10 minutes/frame and frames are finishing in 3-4 minutes, so it seems to have plenty of wiggle room in that regard.



Any ideas are much appreciated, thanks!

[hermit.crab]

Yes, try increasing the subdivisions; also increase the Retrace threshold (Light cache advanced tab) to i.e. 8.

[ecarlsen]

Yes, try increasing the subdivisions; also increase the Retrace threshold (Light cache advanced tab) to i.e. 8.

Thanks! I also tried an approach of using Brute Force for the GI's secondary bounce, which seemed to help but was a bit noisy - any major downsides to using Brute Force for secondary bounce vs. Light Cache?

[hermit.crab]

any major downsides to using Brute Force for secondary bounce vs. Light Cache?

Slower render times.