I have had a few issues with lightmaps from Blender to UE4. Things such as UE4 not wanting to auto generate any light maps for assets created and exported from blender into .fbx.
Assets randomly on re-import deciding to not update lightmap changes. The settings being used in UE4 are all correct I have no issues with other 3D modeling software’s to UE4 its just with assets created in blender. Only thing I can think of is that there might be some kind of export option I am missing when exporting to .fbx?
A few additional irritants, if the mesh in blender has been given no UV or material, then the .fbx imported into UE4 will refuse to generate lightmaps for the mesh, even when the mesh has been given a UV, UE4 seems very random on if it wants to generate a UV using the usual
Here is an example of one issue I am having:
Left (inside blender) Right (Inside UE4)
It looks as if UE4 is trying to generate a UV’ but I have never had it do such a bad job. Lightmaps just seem really random/bad when using blender exports as .fbx.