Hi all,
This is a bug that has plagued corona for years - i havent been able to solve so if someone can help provide a solution or have the bug fixed that would be great.
So i have a plane background (purple plane) and have unchecked cast/receive shadows - everytime i do this to a plane, i get weird shadow artifacts - can you please let me know what the solution or if this is a confirmed bug?
Thanks
Same here.
Host software, OS, and Corona version, please.
Latest corona… 3ds max win10.
Hi,
Latest as in v9 HF1 or a daily build? 
Did you try rendering with the adaptive light solver disabled also?
And lastly can you provide a copy of the scene? Instructions on how to do this can be found in my signature.
Cheers!
This is a known bug, reported many times on the forum and over the support portal, and there are some workarounds to it. Unfortunately the workarounds are not perfect. Generally it is best to avoid such “fakes” as objects which don’t cast shadows or lights that don’t emit light.
The issue is under “black highlights” here:
https://support.chaos.com/hc/en-us/articles/4528311915025-Known-bugs-and-limitations
The workaround is here:
https://forum.corona-renderer.com/ geosphere as background #msg181607
Thanks mate.
Having a background plane showing the views are quiet important in many of my projects - so i would consider it an essential thing to fix.
Are there any plans to fix this bug?
Yes, but as the article states:
These issues are some of the most commonly encountered by the users, yet they are extremely hard to fix for our development team. Corona is intended for realistic, physically-based rendering, and the following issues usually appear if non-physical (“fake”) properties are used for objects and materials.
So it’s not impossible then 
Yes, but even if it was, our developers had already fixed some impossible issues and added impossible features, so nothing to worry about.
Hi team
When is this problem likely to be fixed (if at all)?
2 years gone and still this issue persists.
Corona is physically based as much as possible and fakes are not always welcome.
The issue here is that receive shadow parameter also conflicts with reflections, as you cannot clearly distinct what is shadow and what is a reflection from/in that shadow.
Try disabling visible to reflection/refraction as well, see if it brings any improvement.
But workaround(s) has been available for quite some time.
You can use rayswitch material with no GI slot to “disable” that object from light calculation, which will also disable the shadows cast from/by it.
