Light through wall

I’m having a problem with a stationary directional light on stationary mesh and I’m unable to fix it. Light filters through the wall, but only one; others don’t have the same problem even with the same exposure. There are also some small shadow artifacts.

I read that it could be a problem with the mesh actually having a gap so I recreated the walls.

I also read that the light on two sides should be activated.

I also tried to remove the reflection sphere, increase the resolution or set a specific lightmap.

Nothing worked. I hope someone can help me.

I think you’ll find it happens elsewhere if you move the light.

Does the mesh have depth? If it’s just a plane that won’t help.

Thanks for the reply :slight_smile:

It’s a mesh imported from Blender: I started from a cube for each room that I solidified individually and then join it, in doubt that it did not recognize the thickness. The first time I created it I always started from a cube and I worked only with extrusion, yesterday I thought changing the method.

The strange thing that happened is that once I imported into UE4, some walls were gone and flipping the normal didn’t help so I solidified again with a small thickness and the walls reappeared.

I tried to put a very thin cube in the middle of the problematic wall: it worked until I built the lights and then the problem returned.

I tried to play with the light a bit to see if there is other bleeding on other walls: Yep, the light thruogh everywhere.


I solidified planes to create the walls and didn’t join them. I made each wall rest on the floor and gave it thickness. I then covered the thicknesses that remained visible from the outside with a cover made from a simple plane, extruded around the entire perimeter of the house. I exported the meshes without joining them.

I think the mistake was that the walls rested sideways to the floor and perhaps also that it had no thickness.