Hi
Simple scene - room, cylindrical background with light material applied. Please, check the reflection on the wall opposite to the wall with windows.
Wall material - reflection glossiness from 1 to 0.7 makes reflection of the background object darker, from 0.7 to 0.6 makes it brighter, lower than 0.6 values do not affect the reflection brightness.
Max scene attached
Tested with Corona 6 and Corona 7 DB 2020-12-01, Max 2021 and 2014
Hi, this is a known bug, but also a nasty one. It is listed here: https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180
This is one of the cases where Corona is not able to cope with “fakes” in a way that would be expected by the users. We do understand that this is very problematic, and would love to fix this, however the fix is not trivial.
I am attaching a new version of your scene with a workaround applied. Unfortunately it changes the appearance of the background reflections. Here is how it was done:
I hope that you can use this workaround in this case.
reflection-lightmat-bug-workaround-2017.max (1.36 MB)
Thank you very much Maru!
I use this kind of backgrounds for very early stages of the projects, for final shots if I keep those flat backgrounds (to hide to holes between trees, houses, etc.) they mostly hidden by objects in front of them and do not affect the reflection on the walls that much. But it took some time to find out what gives those annoying stains on the walls and where they are coming from.
Now I’m going to use the workaround offered by you in my workflow, thanks a lot.
BTW, I tested my old scene with new physical material assigned to the walls, and got the same kind of stains with low values of roughness.
