I have forest render, a lot of trees, and with even high Sampling setting of 9 9, I still experience small flicker. Here is the really really short video, where I hope you can see that flicker.

https://vimeo.com/54136057 [vimeo.com]

Noise level seems does not influence this flicker at all. Scene is light with Env light and one Direct light. It flicker with Env light be Direct or AO. PBR, Env sampling is one. I am not sure is it worth setting Env sampling more or control noise with render settings? Is there something else I need to do, except pushing Samples even more?

Have you tried increasing the sampling on the object geometry as well ?…here are a few things to look at.

1. The sampling level on the object itself (render tab >dicing tab on the geo node)

2. Decrease the size of the Noise Level on the Mantra Rop from its .05 default to .01 or .02

3. Min and Max Ray Samples on the Mantra Rop under sampling. Try 2 and 16 or something like that

4. Maybe try gaussian 3x3 as your sub pixel filter.

Thanks Jordan,

Already tried 3 3 gaussian not much help though. Is Shading quality that you are referring on Dicing tab?

Will play more with Min and Max Ray samples and Noise level I guess.

It might be because of opacity maps on leafs? Filter is Box on them, to get a bit faster rendering.

Flicker like that is typical of a low res depth map shadow. You have not mentioned what shadow you have generated for your renders.

Rob

Raytracing. It is known problem with every render engine, I guess only way to lower it to acceptable level is to raise Pixel sampling, AA. Right now I think that I gain most (render time/flicker ratio) with raising Min Ray samples value. AFAIK that influence Env sampling, right?

I would also look at the ray tracing bias. Ive found large scence scales and fine detail like fur in the past has buzzed . It looks like your dealing with a forest of trees with lots of fine detail. It would be great to get a scene file with a single tree for people to look at.

Rob

Scene is large, 2000 units or more. I will try to raise the bias to 0.1? What exactly does that do, read help but … ?