Source of grains in my scene??

[damanjeetsingh]

Here's is a portion of an Interior render that I'm doing in 3ds Max using Mental ray. You can notice the noise and grains in bizarre amount on wall and on ceiling and I have no idea what's causing it. To detect the source of these grains, I tried disabling the environment, which in this case is mrPhysical sky. It does remove the grains... What setting m I missing?

High anti aliasing settings does decrease this noise, but there's got to be some other culprit behind it and I think the Anti-aliasing Engine in Mental ray is being forced to work unnecessarily on something it's not supposed to.

 

Thanks in advance for answering.

Regards.

[Chris MacDonald]

You need to increase your material (reflection) sampling settings. Not sure how to do that in mental ray (haven't used it for many years now).

[damanjeetsingh]

Thanks for answering Chris. but that didnt work either... for some reason, only turning off the environment removes the noise totally, even bumping up the Anti-aliasing setting to Min-1 and Max-16 decreases the grains to some extent, not entirely... :|

[Tom Sproule]

Did you try increasing your light samples as well as the material samples?

[Francisco Penaloza]

Two things,

First, check that any of your light are not behind frosted glass or indirectly illuminating your scene with a blurry reflection material.

Second, samples, 1-16 is a low sampling value for glossy reflections. If you are using the new unified method you'll need to increase your sampling to 1- 60 or more depending your lighting situation and materials.

What version of Max are you using?

What type of lighting are you using?

What method of GI are you using? FG only, or photon mapping plus FG.

are you using the new unified IBL method?

please post more information to correctly asset your problem.

[Tom Sproule]

Hey, if you uncheck 'probalistic lights' in Vray Global Switches (Expert mode) you should be fine with 16 samples. When you have probalistic lights you can get a LOT of noise.