reflection artifacts behind refracted glass

[Juraj]

I had this issue some time ago, but it seems to reappear on random basis. Any material, any angle. Sometimes it goes away automatically..

Anyone had similar encounter ? It's not because of specular maps, the bug appears (although in smaller fashion) even if only diffuse is used. Third screenshot shows it on completely matte surface.

[Juraj]

Simply hiding glass in windows makes issue go away.

Also making the glass "thin" solves it, so that ties this to refraction, but which I need.

[maru]

To me this looks like this (first point):
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180
Temporary workaround is to use thin glass or rayswitch (I'm about to check it and write more detailed instructions).
All I can say is I hope this gets fixed soon...

[pokoy]

A really nasty bug. Working around this with thin glass is not viable in some cases so a fix would be highly appreciated!

[maru]

Quick workaround. But it's not perfect. The glass is simply invisible in reflections...

[daniel.reutersward]

I had a similar problem here:
https://forum.corona-renderer.com/index.php/topic,5375.msg36697.html#msg36697

If I recall correctly the only way to fix that problem was to use the "thin" option (as stated in this thread also).

I really hope this will get fixed as well...

[Ondra]

Yes, it is another instance of the bug maru linked. Unfortunately currently there is no 100% solution. We will have to wait for a future rewrite that will solve it.

[shortcirkuit]

hey guys - 9 years later - this hasnt been solved?

[maru]

This specific case should be resolved, at least when using the Corona Physical Material, which is the default since a few versions.
There are still some cases where "dark highlights" may appear when using non-physical effects, see: https://support.chaos.com/hc/en-us/articles/4528311915025-Known-bugs-and-limitations