Put a decal with a transparent backrgound on a block and you’ll see that the edges are jagged. There’s a comparison below with no decals and it’s smooth.
See steps to report a bug here, there’s more info that could be added:
Please Read Before Posting: Steps to Report a Bug
EDIT: By the way, I’m seeing a similar artifact without any decals:
If you remove the decals is the effect still there?
mhm, looks like ambient occlusion may be causing it.
It is definitely the ambient occlusion. Someone noticed this the day MSAA went live, actually.
Oh, I was having this problem with a union and thought it was a CSG issue. Good to know what it is