Importing entire world back / modified in DCC after exporting

The requirements are the same as with any mesh: make sure that the world is exported as a fbx and that it has the proper textures and materials. However, if the world is too large, you might run into the import limits: I believe it's 500 meshes and 50MB. If you stay under those limits, and it has the proper configurations (fbx, texture, materials) you should be able to import it into your assets.