Those are from having UV Island that do not meet up and also low res Light Maps(LM). You can try to increase LM resolution or re-make the LM so that it has fewer seams.
Thanks Sam. When you say ‘UV Island’, I assume you mean faces in the UV that aren’t connected? The LM’s are high - 2048.
Also, In other scenes it appears to be ok, however in this scene it seems to be exacerbated. Could there be any settings that are actually exacerbating the problem? Again, this is someone else’s scene so I’m not sure what’s been changed.
Also, the material goes from hi-res to low-res when this occurs. Given the LM’s and materials are on a different UV channel, would the mistake in the LM’s cause problems with the material also?
Hi!
We are having the same issue.
The level had nice lighting on UE4.7, but after update to 4.8 started to show many artifacts just like shown above.
Rebaking or playing with settings doesn’t help. We also had a problem much alike in behaviour with textures, which was temporarily resolved by switching off texture streaming.