Light problem

I have a ceiling but light still seems to shine through and casts shadows on to the wall? Lightmaps are auto-generated when importing but I think it’s fine as my 1st UV channel is properly mapped in 3ds max. Help!

Btw, complete newbie here, especially on lightmaps. Been working with 3ds max + vray for my work so far, hope UE can be my next tool!


It is possible that either the ceiling has zero thickness. Try to activate in Details of ceiling parameter - Cast Shadow as Two Sided.

Totally forgot about this as I ended up using a box for the ceiling instead of a simple Plane. But this may be the solution to my problem and I’ll give it a try! Thanks!