Square Artifacts

[lolec]

I'm getting strange square artifacts in some images. (caustics enabled in render rollout and on every material) DOF enabled.



I suspected Nvidia denoising but it happens when it's on or off.

Probably unrelated but just in case it helps, the previews for Quixel Bridge starter looking like this a couple of days ago.




I remember seeing something similar in the forum, couldn't find it.

Thanks.

[romullus]

Did you try to right click over artifacts in the FVB? Maybe it's just a display thing, meaning your GPU is dying?

[TomG]

More info always helps too - which host software, which version of Corona, and the scenes themselves via private uploader never hurts too (looks like they could be just simple scenes). Do they happen it caustics are turned off? If using the daily build, did you try disabling "Enable caustics adaptivity" (in the devel/experimental rollout)? You say "just started happening" - what changed in that time, did you update to a new version of Corona, did something in the scenes change? If you rollback changes (whatever they were), does the effect stop happening?

[lolec]

Hi Tom, yeah, sorry about the lack of info. I was so sure I saw a similar problem in the forum recently, that I thought someone might just recognize it.

Host software 3dsmax

Using the latest daily build.

It does not happen without caustics.

Motion blur is activated in geometry.

Some other interesting detail:  I rendered the same frame multiple times. Some squares stay the same, while others change slightly.

Actually, I managed to get rid of the squares by disabling caustics adaptivity.

I'm in the middle of an important job and can't really do a lot of testing, but I will come back to the scene and do some investigation once the job is over.

[TomG]

Aha, the very reason that checkbox (disable caustics adaptivity) was added. Adaptivity, as the name suggests, picks which areas need caustics and which don't, and how much to focus on the bits that do. This speeds things up, but in some cases it can't pick correctly, and artifacts can appear. Disabling it avoids those, but will render slower. However, slower and without artifacts is the better choice in such scenarios!

[mferster]

It's definitely related to your material. Have you tried turning your maps off one by one to find which one is causing the issue?