Map onto Non-flat Earth

Question

How do I put an image (Google Maps satellite view, flat to start with, later to be 3D topology) onto a part of a sphere?. The map is of an Earth region a few miles long, and I’d like to model it as accurately as possible, e.g. the correct visible distance from a standing adult’s eye-level above surface to horizon.

What is the best way to do that?

Or is it necessary (or simpler) to define the whole sphere and then zoom the viewport and rendering view onto just the required part ? I can see that for a uv sphere, this would imply a massive number of elements (faces/facets, nodes, edges...).

Answer 1

I've never done this, but I think you would get most accurate horizon distance, if you use UV Sphere with radius being average Earth's radius in your region and then work from there (remove all the surface area you are not going to need, subdivide faces at remaining region, apply uv texture), though its hard to tell if this method wouldn't be overkill or too inaccurate, depending on size of your region.

You can calculate Earth's radius at specific latitude with tool like https://rechneronline.de/earth-radius/

As for the textures - it is worth noting that no satellite photo is "flat" (like drawn map) and google maps doesn't display them on flat surface either - it is already mapped onto sphere, so you would have to map UVs "from view" (with viewport having as close settings as camera that took original image), again - maybe more work than needed, depending on region.