Render noise

[Luca.Buettner]

Hello,

I am an interior design student from Germany (so I am a complete noob). Since this term we render images in vred (after import from alias). Everything worked fine until a fellow student rendered some of his stuff on my computer. After that every render I did looks grainy and distorted. Denoiser is way to aggressiv to be useful. Number of render samples makes no difference. I reset the preferences, I set the render settings to default. Nothing changes. 

More infomation: The grainy image (Studio Environment, exposure 0.05) (other exposure settings make no difference), Antialising and Raytraicing are activ. Worked fine on my grafics card. 

I think its the two objects that emit light. (plan is two set the environment dark and set focus on that area) (plastic white, Incandenscence: Intensity 60)

I am sorry to bother you. It is probably a very simple mistake I made. 

Thank you for your answers. 

Greetings Luca Büttner

[michael_nikelsky]

Have you turned on the "Use as Lightsource" for the incandescence materials? 

Another idea, if you don´t have too many lights, can be to disable the Optimize for many lightsources option in the Render Settings. 

[Luca.Buettner]

First of all. Thank you very much for the quick answer. 

I followed both of your instructions.

It solved the problem to a certain degree. But the "noise"/ "grain" is not completely gone. (as you can see in the image)

That's not enough for my final presentation to the board of MAN Trucks.

Are there some other settings I am missing?

Thanks again. I appreciate that very much. 

Luca

[michael_nikelsky · Accepted solution]

To be honest, this just looks like you are not using enough image samples at the moment. Try doing a region render with the infinite render option set for the viewport and check when the noise disappears. 

If you are using GPU raytracing you might also try to turn on the "Use Two Sample MIS" option. This is a bit slower but can reduce the noise in some cases quite a lot (for CPU raytracing this option has no effect as it is always on so I am currently thinking of enabling it by default for GPU RT as well, to have a more consistent result).

Another thing might be to split up the lightsource geometries in a different way. Not sure how you are currently handling these, if they are all merged or all separate objects. Also make sure the light emitting surfaces are not mostly occluded (like modelled as a thick object that is mostly stuck inside the other object) as this will reduce the efficiency of the importance sampling and require a lot more samples to be clean.

[Luca.Buettner]

Thank you very much. That helped a lot. It's weird because I've always rendered at 256 so far and it worked just fine. 

But that seems to do the trick.

Thank you very much and have a nice day