How to fix blocky shadows across modular walls?

Hey guys,

I’m having an issue in UE4 with my modular wall tiles (static meshes). The shadows on seem to be acting weird on them whenever there is no direct light on them. I’ve had this problem in the past (in UDK) and I always got around it by just using a large BSP/stactic mesh instead but this time I’m trying to keep things modular.

I’ve used the grid in 3dsMax (modifying it for lightmaps (1/lightmap resolution), all the faces are broken apart and have a padding of 4 pixels each. So I think this is correct.

I was wondering if anyone knows why this is happening and how to fix it?

Here’s some images of the walls in shadow and in direct light.




Hi Garasin,

This is a known issue where you can find more information on this previous posted question on the AnswerHub.

You can even take a look at this thread for the same issue.

These seams are caused by Lightmass processing different objects on different threads. There’s no silver bullet to this, but some things you can do to reduce the impact

  • Plan object seams to happen at corners / edges, not on a flat surface
  • Reduce the smoothing done by lightmass in
    A value of .6 or so can work well. You
    might also need to jack up the
    IndirectLightingQuality to 2 or so to
    compensate for this.

The tips here can help reduce it but it’s not a sure fire solution.

Thank you!