For importing 3D mesh maps, see also this topic, the same applies to data that is property of Apple and others.
For exporting the model and viewing it on a map, Google Earth (as long as it still exists) has the advantage that it has an API and import functionality so you can view your own data (models) in it.
See also Placemaker for getting context for your model (although it has no aerial-textured buildings). It uses data under free license, a mindset that is probably much in your interest to support. You can contribute your buildings and building footprints using SketchOSM.