Issues with lighting a blockout

Hi guys,

I’m new to working in UE4 and I’m struggling to understand why my lighting isn’t working. I’m finding that I can adjust lights in the editor so that they look the way I want them. However, when I build my lighting, the lighting then differs. Lights cast on to walls tend to be blocky or sometimes absent. Lights hitting floors often appear absent.

My scene is build entirely from simple static meshes (from the starter content) and a some BSP objects. Probably about an 80/20 ratio. All my lights are mostly spotlights and are set to be static. I’ve tried increasing the lightmap resolution up to 256, but still have problems. Please see the screenshots for examples.

Editor view…

After building view…

The lighting in the editor remains ‘wrong’ until I then move them a little and they return to lighting the scene.

I’m only seeing one error message about some overlapping UV’s, but I’m not able to track down the offending object as the error message doesn’t state which object is the problem.

I appreciate any help!



the static mesh is set to cast shadows? the lights you put there are set to stationary?

Hi Filpe,

The static mesh floor pieces are set to cast shadows and the spotlights are set to static.I have the same problem with some point lights not casting light onto some desk objects when lighting is built.



hmm, ok, it´s probably a bug then.

Good luck!

Anyone? I can’t find any solutions to this. :frowning:

Hi Ellismonster,

From the looks of it your lightmap resolution is too low. The column further down seems to be an indication of this with the blobby shadows, and the edging shadows around the wall pieces.

If this level with all the walls or a lot of them are all combined as a single mesh using a single UV for the lightmap a resolution of 256 would be extremely small. You would have to think about it in the sense that all the flattened faces of the geometry will need to use that UV space, so it doesn’t mean that all the faces will get a 256 resolution, the UV islands will only get a percentage of the 256 resolution. It’s better to break up the geometry into smaller modular pieces when trying to get a good lightmap resolution.

If you’re not sure, feel free to post the UV Channel 1 image from the Static Mesh editor and I can offer some feedback. You can do this by going to the static Mesh editor and clicking the UV button in the toolbar. Then in the drop-down next to it select UV Channel 1 to show the lightmap.

Thank you!


have same problem, have decent lightmap res,( 256x256 for a 256cmx256cm wall block)

still cant get rid of the blocky lightning unless i set the worldscale to a ridiculous .1 which also brings the render times to nirvana… Still not convinced that the Unreal arch community has to set scale so low to get proper lightning.

bdogrular, what lightbuilding quality settings are you using? Have you changed them to high or production and does your lighting still loks blocky?