Denoiser and lock noise pattern?

[ben_hamburg]

Hey there,

been trying to use denoise as often as possible, but when rendering animations I´m still uncertain, whats better..."lock noise pattern" on or off?
I couldn´t find a clear answer to wether it makes a difference.
Since I most of the times forget to check it on and often don´t have time to render another version with lock noise on, I´m not sure if the small noise flickering I still get is due to that option, or due to just too low noise threshold overall.

Can you clarify please?

[vlado]

It depends on the scene and what exactly is being animated. I imagine having the noise pattern locked might help to reduce flickering a bit, but it depends on what exactly flickers. Is the flickering around small details, or on larger flat areas? You could always try more animation blend frames when denoising and see if that helps.

Best regards,
Vlado

[dgruwier]

Lock noise pattern gives you the effect of the noise kinda being stuck to the camera instead of updating each frame. You can see the kind of effect it has here, especially in flat areas. The noise is there, but it's still. Notice how it looks more like something stuck to the camera lens: https://www.youtube.com/watch?v=6zWX5nurr4c

Whether to leave it on or off is a bit of a matter of preference. I personally always leave it off, I think the natural noise updating each frame is much nicer, even if it means higher sampling settings to actually get rid of that noise. That's another issue.