great to know then!
My humble suggestion is then have a global (radius, latitude, longitude) system, and a local (x km, y km ,z km) system. And the user could place the origin of this local system anywhere in the planet where the focus of the scene will be...
![Roll Eyes ::)](https://www.planetside.co.uk/forums/Smileys/fugue/rolleyes.png)
but who am i to say?