Mesh Black After Build

I have a mesh with a simple material which works on multiple other materials. However, this one particular mesh turns black after building despite other static meshes with the same material being fine.


I think you should check out the mesh. Sometimes this happens when your mesh has no UVs and you lit your scene, using only static lights.

Hm, this does appear to be the case. I have ‘Generate Lightmap UVs’ checked, but it does not create these. Do I need to mark seams on my mesh with my 3D software?

Your model must contain at least one UV. If your model has no UV, UE4 does not generate UV for Lightmap. You need to open the model in a 3D editor and add a UV channel.

Thank you! This has helped me get to the solution. I had not unwrapped the mesh, after adding two UV channels and unwrapping the model on the first, it generated lightmaps for the second. Apparently, it uses the UV islands from the first channel to generate the lightmaps on the second channel. This also fixed another problem I was having, where only part of a mesh was lightmapped because only part of it was unwrapped.