Lightmap creates shadow of underlying geometry?


Whenever I build my lighting I seem to get a shadow bleeding through to the other side. It’s as if Unreal detects nearby geometry and bakes a shadow of it on the opposite side. For instance on a simple wall T-section, the flat wall will show a vertical shadow line where the wall is on the other side. I also have this on a bathtub model where I have a mesh plane behind a hole in the bathtub to seal it off. But on the inside of the bath it should bake nicely. My UV’s are clean and lightmap size is also more than enough. It’s as if there is a setting causing this that I don’t know of? These are production bake screenshots that I posted to visually show what I’m talking about. So it’s also not because I’m baking at a lower quality. I tested this in both 4.15 and 4.19, both engines have this issue. I hope it makes sense.


Thanks in advance!