Sun + diffuse bitmap = weird shadow

[Specto3d]

I have weird shadow/artifact when using either corona bitmap or 3ds Max's bitmap.
It happens when sun hits the surface, and it changes with sun's position.
When rendered without any bitmaps, this weird shadow disappears.

Anyone seen something similar and is willing to help?

Thanks in advance

[romullus]

Just a guess - incorrectly setup normal map?

[Specto3d]

No normal maps used on this material.
I removed it but not completely with setting blur under bitmap's filtering to 0.1

[Juraj]

Truth be told, looks to me like that classic refraction issue ? Nonetheless, this is 100perc. Corona artifact.

Specto3d, do you have the sun shining through a glass perhaps ? Or Environment override ? I don't really remember what triggers this.

[Specto3d]

There is no wall or glass behind the camera, and there is no refraction that could cause this.

I've used HDR with CoronaColorCorrect originally and have tried CoronaSky but it didn't work.
Meanwhile, lighting needed to be changed and artifacts disappeared, but it would be nice to know what happened here.

Thanks for your reply Juraj!

[maru]

It's probably one of those fake light transport issues: https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180-known-bugs-and-limitations

We would have to take a look at the scene to know for sure.
Can you share it? https://corona-renderer.com/upload

[gioba]

in 2024 yet still there this problem, yet with an hdri or sun..every time