Generating Lightmap UVs without UV1s

UE4 doesn’t “generate” lightmap UV2s, it just rearranges existing UV1s.

Importing a FBX that doesn’t have any UVs (flat colors) breaks Lightmass.

Is there any way (external plugin, Blutility, etc) to get Unreal to unwrap UV1s so generating UV2s will work ? Or, alternatively, diretly unwrapping UV2 ?

Going through 3ds and hand-unwrapping each mesh is not an option for this project. I’m looking for an all-integrated solution.

Thanks !

Hi Calvin,

You are correct that the generate UVs option does only repack the UVs from the specified Source Lightmap Index.

If you need to do a proper unwrap you’ll have to use a modeling program or one of the many standalone applications that can be used for UV Unwrapping like iPackThat, Headus, Unwrella, etc.

At the moment there are no plans for an in-editor integration that I’m aware of and there isn’t any plugin’s that I’m aware of that have been developed with this purpose in mind.


Thanks for you answer @TimHobson. I’ll have a look at the alternatives you suggested. Currently I use a Blender script that unwraps everything but shipping Blender to the (intermediate) customer is just too awkward.