refracted gi noise

[francomanko]

Hi,

I am getting a lot of noise in the GI pass, when rendering glass, that i cant seem to get rid of, despite raising sample levels etc.

I've attached a few images, showing material and 2 GI pass renders, 1 without glass and one with.

I saw a thread on the max forum which said it was related to the ray depth, i was wondering if this is the case here, or if I should expect noise?

http://forums.chaosgroup.com/showthr...efracted+noise

Scene is lit with one of Peter Guthries HDR,

Brute force and LC (subdiv 2500)
Min shading Rate 2 (have tried 8 no improvement)
Min subdivs 1
Max subdivs 80-200
Threshold 0.01

Any help is much appreciated.

1st image = GI pass with no glass, 2nd with glass...

[Morbid Angel]

its probably because of your fog multipler. Its making the glass slightly dark and terminating enough gi / light passing through that the min threshold of 0.01 is skipping it. You don't need 80 max subdivs. But lowering the threshold should fix the problem. Also what are your color mapping settings?

[francomanko]

Hi thanks for reply. Yeah although there is still a bit of noise turning up the threshold helps, cheers fella I suppose having 2 window planes in each panel you have to expect some noise in there.

My colour mapping settings are

Reinhard
1
1
gamma 2.2
affect background ticked
mode : dont affect colors, only adaptation

nothing else ticked.

[francomanko]

hmmm i just changed GI method from Brute Force to Irradiance and the noise has gone and i can can increase the threshold amount too. Is that a typical result with Brute force?

[Zdravko.Keremidchiev]

Is that a typical result with Brute force?

It looks more like a specific case. If you send us the scene we can investigate further.