I’m getting a lot of noise in Cycles X (Blender 3.0.0). I found no tutorials to address that. I found some tutorials on the older cycles. But some settings are no longer there, such as adaptive sampling.
Has anybody found a solution? The images are 1920x1080 animation rendered to png 16 bit. Very blocky noise in the shadows.
As it’s animation, the noise moves and jumps around, so it’s very noticeable.
Does increasing max samples makes it noisier? Because it seems 128 is less noisy than 1024 (above). I would have thought the opposite would be true. The same is true regardless if rendered in 2K or 4K. But that doesn’t fix the problem. It seems it is just blurring the noise. But in an animation the blurred blotch still moves around.
Noise is very dependant on the way your scene, lights and materials are set up. A single poorly set up light or material can cause a lot of problems, however sometimes it is just the nature of a scene that makes it very noisy. For example indoor scenes with small windows, where the lightrays get stuck in the room and bounce around a lot, scenes with volumetric materials.
Adaptive sampling is now called noise treshold, so that’s the setting you’ve been looking for.
That said, it’s difficult to help finding what’s causing the noise in your scene, without having access to your .blend file. Avoid creating mesh lights with a very strong emmision material, avoid very tiny lights/mesh lights.
Max samples should definitely not make it more noisy, and if it does, it seems like there’s a problem that can be mitigated in your scene somewhere.
Worst case scenario you’ll have to brute-force it and increase the samples enough for the denoiser to produce consistent results between frames.
Any chance you can provide a blend file , maybe if you’re not comfortable sharing the full project just a rough blockout of the scene with just the lights you’re using copied into that new blend file? I’d make one myself, but from the provided images it’s very difficult to tell what’s going on in the scene.
Thanks. This is what I’ve been trying to do. But since it’s a dark scene, adding enough AO to solve the problem means totally changing the mood of the scene, as it then becomes too bright.
Your screenshot looks like a problem I had from adaptive sampling was first introduced all the way up until today’s cyclesX. The only solutions were (a) disable adaptive sampling or (b) add enough minimum samples value or (c) significantly increase the amount of light in the scene and then darken it with the Exposure setting.
Basically not enough light is getting to those areas and the denoiser has no idea what to do with that lack of information. But there are also times when a lot of light is getting to the problem area and it continues to look ugly after denoising. In that case more minimum samples or disabling adaptive sampling is the only fix that worked for me.
Ok, just rendered a couple of frames. Doing the above, despite looking less noise, the shadows still move/oscillate from frame to frame. Almost as if it was lit by candle light or something.
If you can and don’t want to go crazy with samples, try filling out the dark shadows with some additional direct lighting. I sometimes use a tiny hint of global AO, and that additional brightness can help bring the denoiser artifacts down. Lighting mostly with low intensity indirect have caused issues like these for me in the past. Or render out only problematic areas with more samples.
What should fix it is as Thinsoldier and Carlg suggested, add some more ambient light so the denoiser has more information to work with and can achieve a more accurate denoised result, and then bring the exposure down or adjust the image in the compositor to achieve a more contrasty/darker look.