Quite bad noise on PT renderings - how to deal with it?

Here is environment I am working with:

Converted to USD with the latest UE connector.
Here is a rendering made with Path Tracing, 128 samples, no motion blur. average rendering time 7 min/frm:

As you can see the noise is too much. So raised the samples to 256. No motion blur. average rendering time 11 min/frm:

Still quite much noise… But before I raise the samples, is there something I could do with the most noticeable source of noise, the reflection of the two lights at the wooden panel, at low left corner?

What GPU are you running on? That seems really slow for that number of samples on that scene.

I have RTX 2070 Super
Studio driver ver 471.41

I know, this seems to be really slow. Maybe it is the Evermotion lights that are converted in not so efficient way…

I send the files to you as PM so you can check it out if you have time. Thanks Revl!

I deleted all the UE lights, there were many emitter objects and strange solutions… They must work nice in UE but here they just mess up things.

I learned from this that I really have to build my lights manually in the end, before rendering. That is a good thing cos that´s my thing anyway - I am in the end a cinematographer.

Here is a fast render with Pat Traced 50 samples and motion blur 4, rendering time 1min 20 sec / frm:

I think I can work from here :D

Lights rebuilded from scratch!

1 Like

I agree that lights exported from Unreal by the Omniverse USD plugin don’t always do the right thing in Create, but I’d like to get to the bottom of this issue and see if we can do a better job of exporting them. I know that I have access to this scene, but if you have any of these answers available quickly, then it will help direct us:

  • What kind of lights are giving you the biggest problems (spot, point, rect, direct, etc)?
  • Are any of them using IES light profiles?
  • Is it the intensity, shape, or size that’s causing problems?
  • Are you finding lights that are recessed into geometry cause problems?

I sure shall give you this info. But now I have to hurry up to deliver the job… Sorry for the delay.

I had to also change some materials to Omniverse natives to render without too much noise.

Typically you need at least 500 samples to reduce noise. Its often better to have some motion blur as well to help.

1 Like

The best solution here was to raise the ISO setting of the render settings / path traced / post processing / tone mapping / ISO 800

Then I could use lights with much less intensity, and that cut down the overall noise on renders. Anyway, I had to rebuild the lights from UE scene and that´s what I shall always do anyway.

1 Like

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.