unstable noise in the animation

[fabio81]

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

[Beanzvision]

Hi, can you share a still and possibly some settings with us? If that's not enough, we may request the scene file.

[fabio81]

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-
now there is a pass limit of 5 to see if you notice that the noise is not stable
lighting with only sky + sun

[romullus]

In render setup/performance there is an option called lock sampling pattern. Make sure that it is checked ON.

[fabio81]

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

[Beanzvision]

I made the camera stationary to focus more on seeing the noise, this is 90 frames rendered.
https://streamable.com/rveju

[fabio81]

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?

[fabio81]

I also tried in another scene but I have the same problem. I wanted to understand if this is right?
thank you

[TomG]

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.

[fabio81]

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?

[TomG]

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 ;)

[fabio81]

I will do tests with denoise AI and Denoise Final and then I will let you know. thank you so much

[fabio81]

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-

the GIF example at the end of the page

[fabio81]

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

[Nejc Kilar]

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