a graphic editor and GIS to prepare the image you are working with for processing in CubeMap. GIS is needed in order to reproject an image from a cylindrical projection into a cubic projection. The image that you received after reprojection should be cropped as needed.
That gives me more questions than answers lol
I sort of get this, but, for example, the grand canyon:
I wanted to do this exact same thing for a region close to me, how would I go and do that? I can get the height maps and diffuse maps from global mapper, but how do I add them into space engine as tiles with their respective level of detail and position in the texture?
Also what GIS software are you referring to?