Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: fabio81 on 2019-01-29, 10:54:45

Title: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 10:54:45
Hi guys,
I looked at many posts on the forum but I have not yet solved the problem. I'm trying an animation without objects in motion but between a frame and the other the noise is not fixed but always variable.
I saved the uhd cache as per manual but I do not solve the problem. I'm using a fixed pass limit
Is there any new guide by chance?

thanks
Title: Re: unstable noise in the animation
Post by: Beanzvision on 2019-01-29, 11:06:32
Hi, can you share a still and possibly some settings with us? If that's not enough, we may request the scene file.
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 11:22:39
Hi Beanzvision! Thanks for the reply.
for the settings I followed this guide
https://coronarenderer.freshdesk.com/support/solutions/articles/5000501664-how-to-setup-animation-flicker-free-pre-1-0-hd-cache- (https://coronarenderer.freshdesk.com/support/solutions/articles/5000501664-how-to-setup-animation-flicker-free-pre-1-0-hd-cache-)
now there is a pass limit of 5 to see if you notice that the noise is not stable
lighting with only sky + sun
Title: Re: unstable noise in the animation
Post by: romullus on 2019-01-29, 12:22:23
In render setup/performance there is an option called lock sampling pattern. Make sure that it is checked ON.
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 12:28:57
In render setup/performance there is an option called lock sampling pattern. Make sure that it is checked ON.

I have verified and is on.
Can you also try on a simple scene?
I attach a test, and you can see that the noise changes position at each frame
Title: Re: unstable noise in the animation
Post by: Beanzvision on 2019-01-29, 14:22:54
I made the camera stationary to focus more on seeing the noise, this is 90 frames rendered.
https://streamable.com/rveju
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 14:28:46
I made the camera stationary to focus more on seeing the noise, this is 90 frames rendered.
https://streamable.com/rveju

What animation is with the fixed camera?
can you try my file and make that?
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 16:51:01
I also tried in another scene but I have the same problem. I wanted to understand if this is right?
thank you
Title: Re: unstable noise in the animation
Post by: TomG on 2019-01-29, 17:02:26
Thing is, noise is comes from the fact that sampling is random, so it will be... random :) As it converges toward a clean image, that's where "lock sampling pattern" will show up. I guess the real question is, why is this a concern at this early few passes? As things converge to a clean image, this won't be an issue anyway.
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 17:09:19
Thing is, noise is comes from the fact that sampling is random, so it will be... random :) As it converges toward a clean image, that's where "lock sampling pattern" will show up. I guess the real question is, why is this a concern at this early few passes? As things converge to a clean image, this won't be an issue anyway.

Hi TomG thanks for the reply :),
the problem is that having a noise all the same, I'm much less likely to see since the denoise will clean in the same way. Instead having many different noise combinations, this will be seen in animation. I would like to create different animations with a pass limit of 5% and AI denoise to clean up but if I have this result I certainly could not present them.
On your site I have seen that the noise remains constant, why now it is random?
Title: Re: unstable noise in the animation
Post by: TomG on 2019-01-29, 17:19:17
By the time it gets to 5% with denoising (though not sure I'd recommend the AI denoiser for final rendering), you shouldn't see any difference. If you do, well, that would be the time to post that there's a problem :)

PS - I don't know what you mean about "on your site I have seen that the noise remains constant"?

PPS - If this was an issue once you get to a clean image, then there simply wouldn't be any animations with Corona, and there are a lot ;)
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 17:21:54
I will do tests with denoise AI and Denoise Final and then I will let you know. thank you so much
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 17:25:33
PS - I don't know what you mean about "on your site I have seen that the noise remains constant"

https://coronarenderer.freshdesk.com/support/solutions/articles/5000501664-how-to-setup-animation-flicker-free-pre-1-0-hd-cache- (https://coronarenderer.freshdesk.com/support/solutions/articles/5000501664-how-to-setup-animation-flicker-free-pre-1-0-hd-cache-)

the GIF example at the end of the page
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-29, 17:36:33
this is done with 30 fixed pass (noise about 7%) denoise AI to 1 and you can see flickering noise on pillows, glasses and plants. Is there a way to fix this? if I had to render everything to noise limit 4% it would take me too much time
is it better to use a pass limit or noise limit?
thanks
Title: Re: unstable noise in the animation
Post by: Nejc Kilar on 2019-01-29, 17:50:17
Hey fabio81,

Do not use the AI denoiser for final frames :) It isn't meant for that, it has no temporal coherence and it does a "rougher" job cleaning up the image than the high quality denoiser.  Don't think the HQ has TC either but it does a more precise job at preserving edges and details.

I suggest rendering to about 5-6% and denoising at 0.5 . I think those numbers worked good for me in most cases.

To quote the helpdesk - Fast Preview Denoising should be used mostly for interactive rendering, quick previews, and optionally for final stills (High Quality Denoising is designed to be used for high quality stills and animations)

I also totally agree with Tom, obviously the random sampling will look horrible when you've got 10 passes and everything is super noise. Once you get to a cleaner result I think you'll find that the noise is a lot more subtle. Unless something went wrong, heh :)Hey
Title: Re: unstable noise in the animation
Post by: TomG on 2019-01-29, 17:52:55
Yep, had already recommended not to use the AI denoiser for finals :)

Also, for animations where the eye can compare frame to frame, sometimes you just need more passes. The brain is very good at spotting "differences" between images, so a single still it may not be obvious, but in an animation you just may need to run to a lower noise limit. Not a Corona thing, just the way it is with all progressive rendering.

Also, you can look into baking the UHD Cache for a flythrough style animation where only the camera moves (https://coronarenderer.freshdesk.com/support/solutions/articles/5000515648-how-to-use-uhd-cache-for-animations-and-stills-)

Title: Re: unstable noise in the animation
Post by: Noah45 on 2019-01-29, 18:02:44
The trade off is, from my experience, either a ~1/2hr to 1hr frames w/ high quality denoiser @ 7% or use the AI denoiser @7% and 5m frames.
The difference is some materials need to be adjusted, ie. fine details bump maps,some metals.

Realtime render Corona?
Title: Re: unstable noise in the animation
Post by: fabio81 on 2019-01-30, 09:30:37
Hi guys,


this is a test done with 70 fixed pass (about 5.5% noise) and denoise High quality

https://drive.google.com/open?id=1lzAG0Ny1KmVDP3bwp4aZhrI9KQpdEPuB (https://drive.google.com/open?id=1lzAG0Ny1KmVDP3bwp4aZhrI9KQpdEPuB)
Title: Re: unstable noise in the animation
Post by: sirio76 on 2019-01-30, 19:21:33
Hi guys,


this is a test done with 70 fixed pass (about 5.5% noise) and denoise High quality

https://drive.google.com/open?id=1lzAG0Ny1KmVDP3bwp4aZhrI9KQpdEPuB (https://drive.google.com/open?id=1lzAG0Ny1KmVDP3bwp4aZhrI9KQpdEPuB)

Hi Fabio, ask me about this problems on Slack;)