Lighting disappears after build

[AndyEdock10]

@darthviper107

If that’s your lightmap UV then it’s very bad, looks like you used automatic mapping which often gives bad results. Ideally, you want to unwrap it yourself so that you can do a better job
for best results, use as few seams as possible and try to keep the UV islands similar in size and try to use up as much of the UV space as possible. In your case, you may need to split up the mesh into multiple pieces to get enough detail because it looks like it’s a large mesh and you can only use one lightmap per mesh.
In your case it also might be the lightmap resolution that’s the main issue there, if you didn’t change it from the default then the default is 64x64 pixels which is way too small for that.

increasing the lightmap resolution to 4096 does fix it somewhat (it’s not black anymore but the lighting result is quite bad). Breaking the mesh up into smaller parts makes sense, I’ll try that. I’m not particularly good at manually unwrapping UVs, so hopefully the auto generated ones work if the meshes are smaller. Thank you!