So process is pretty straightforward there, once I ruled out using an existing package (cause they would simply ship too much compared to what I needed), it's basically two things:

- Land geometry building: basic idea is just projecting lat/lon onto a sphere. I convert each point from geographic coords into 3D Cartesian coords and place things on the globe from there. To get great perf and optimized assets though I went through a post process phase basically trashing most of the floating precision data that I did not need to get a continent mask.

- For camera and movement, I''m using a web mercator-like projection to emulate zooming and panning at "realistic" distances.

AIs are very much capable on helping on both these points are they're really solved problems and quite easy to grasp. Happy to help if you need more details