Modelling of Atomium is possible with Simple 3D Building 2.0
This specification (and modeler) is the main topic of master thesis of my student 
But please, be patient, we need some months of work.
Nice example is the cathedral of Durham:
http://demo.f4map.com/#lat=54.7728492&lon=-1.5765523&zoom=19&camera.theta=57.032&camera.phi=-22.918
Extremally complex:
Moscow Kremlin: http://demo.f4map.com/#lat=55.7511383&lon=37.6188031&zoom=18
The craziest 3D Model around the world is probably national stadion in Warsow (wait some second for rendering, the model is extremally big):
http://demo.f4map.com/#lat=52.2390241&lon=21.0453083&zoom=18
If you have modeling questions please ask. Note: You can use in JOSM the Kendzi3D plug in or improved Kendzi 3D. You see changes immediately. In other Editors you have to wait ca 18 hours for rendering in F4 maps.
and of course, it is a lot to do. But start with very simple buildings and see results.
Best regards,
Marek