Square tiling of a sphere #

I almost always work on 2D game maps, but occasionally I get intrigued by planetary maps. I'd like to make a planet that uses a grid. The topology of a sphere requires a few things:

  1. Moving east or west you eventually wrap around the world → easy
  2. Moving north/south you eventually reach a pole, and then all directions are south/north → medium
  3. Wrapping around the world east/west is shorter near the poles than near the equator → hard