That’s an interesting question… I know that from inside UE4 you can wire a value to the emissive node in any material, and bake that material as a static light, but I’m not sure if I’d recommend trying to accomplish that in the graphics software itself; I’ve had some problems importing anything more than the simplest channels into Unreal with the fbx, to the point that I’ve settled on importing objects with a blank material and wiring in all of my textures and cool stuff inside the engine.