Hello
I don’t know why, but when I click to mesh or I placed the mesh on level then doesn’t work properly. If I go in mesh then there is no walls and other things.
Image:
As you can see left side in blender and right side in Unreal Engine 4.15. I don’t understand why this happening.
Here is the asset if this is easier to understand.[link text][2]
If I import in blender the fbx file then it shows correctly but not in unreal engine.
I would imagine the issue here is that your normals are flipped, I can’t remember how this is done in Blender, but you should have an option such as flip faces, or flip normals. Obviously not all those faces need to be flipped though.
Try setting your materials to 2 sided, if the poly share both an inside and outside…side they will work correctly once you set your material to 2 sided:
Also just a side note 84 materials is a lot of materials and draw calls for a single mesh, you may want to try to consolidate them or do an optimization pass for them, just FYI.
Yep, it works. 
Thank you very much. 
