Caustics flickering in animation

[hacain]

I saw someone else's post and it's the same symptom as mine!

I'm currently working on a project, but I've been testing it all night for 4 days because of this problem, but I haven't solved it.

I'll send you a simple set-up of the test scenes

Help me.

[hacain]

I'll give you information about my work

My current work PC is Threadripper 3970x and 128 RAM
Randerfarm has 3900x and 64 gigabytes of RAM

Flickr's symptoms now occur even if you render it with a backburner on Rander Farm, but the same symptoms occurred even when you tested your work with just one computer.

I've looked at all the posts on the forum and tried all the tests I could, but they don't disappear at all.
Please help me

The number of cases I tested is as follows

1.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 1

2.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 2

3.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 4

4.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 8

5.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 16

6.
Scene setting - Noise level 3% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 1

7.
Scene setting - Noise level 3% / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 8

8.
Scene setting - Pass limit 64 / No Denoising
Performance - Caustics Solver ON / UHDCache - Animation - Precision 8

9.
Scene setting - Pass limit 64 / Denoising - Corona high Quality
Performance - Caustics Solver ON / UHDCache - Animation - Precision 8

10.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / 4K Cache - Granularity 1 - Quality 1

11.
Scene setting - Noise level 5% / No Denoising
Performance - Caustics Solver ON / Path Tracing

[maru]

Hi, rendering flicker-free caustics in animations may be challenging right now. Trying with different UHD/4K settings probably won't make any difference because the issue is in the caustics solver itself.

One idea is to "cheat" a little bit by using the Corona Rayswitch map in the opacity slot of the water material. The opacity should be white for all Rayswitch slots and a little bit darker for the GI slot. You would need to find the right value between "the flickering is still there" and "the water is overall too bright". I would suggest something between 70 - 90% brightness. More instructions are here:
https://forum.corona-renderer.com/index.php?topic=31171.msg178222#msg178222

You can also enable the development/experimental stuff rollout (https://support.chaos.com/hc/en-us/articles/4528523195537) and increase the caustics solver photon count. The instructions are also included in the above link.

The last resort is loading the animation into some kind of 2D editor like After Effects and using noise reduction / anti flicker filters that are able to keep temporal consistency between the frames.

I will test your scene and try to find render settings that would work good.

Sorry for the inconvenience!

[maru]

(also note in addition to my above post: I don't know what environment lighting you were originally using as in the attached scene the 3ds Max enviro window crashes my Max as soon as I press "8")

[hacain]

Thank you for your answer
I didn't use anything other than the environment that was applied to this scene setting
But I reset the blinker and solved it to a certain extent

I applied the noise effect only to the bump and display map of the water and reduced the details, so the blink decreased significantly.
Among other posts, it was said that it was better to change the display map to a world size than a screen, but it was not rendered, so I used it as a screen for now.

[maru]

Here is the result of rendering with the "fixes" I suggested:
- rayswitch map used in the opacity slot with 85% white color for GI
- photon count increased to 15000
- 100 passes rendered per frame
- (UHD Cache set to "animation" preset)

Attaching the scene and animation.

[hacain]

Oh, thanks for the answer. I'll try