Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: Specto3d on 2018-08-31, 21:28:48

Title: Sun + diffuse bitmap = weird shadow
Post by: Specto3d on 2018-08-31, 21:28:48
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
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: romullus on 2018-08-31, 21:54:16
Just a guess - incorrectly setup normal map?
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: Specto3d on 2018-09-03, 15:21:51
No normal maps used on this material.
I removed it but not completely with setting blur under bitmap's filtering to 0.1
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: Juraj on 2018-09-03, 15:36:03
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.
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: Specto3d on 2018-09-03, 17:25:13
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!
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: maru on 2018-09-04, 12:44:06
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
Title: Re: Sun + diffuse bitmap = weird shadow
Post by: gioba on 2024-02-22, 10:18:54
in 2024 yet still there this problem, yet with an hdri or sun..every time