In the meantime, could you supply us with a process or reference by which we could proceed the hard way? Like a formula: f(x,y,z and center geocoordinates for the model) equals (lat, long, alt) for each vertex.

I'm somewhat confused about the distinction between a polar coordinate system and your equirectangular mapping with altitude. Seems to me they are equivalent. For conversion to polar, assuming that x,y define the horizontal plane and z the vertical dimension relative that plane, we would also have to specify geocoordinates and altitude where the model center is positioned, as polar coordinates are not locally invariant.

No need to get comprehensive. Just point us in the right direction and we will be grateful for the kindness.

I'm also very curious how (or even if) you could make UV mapping work with your system?

SMcQ