Thanks, but I have not much merit, Fractal Terrains did the entire job, mostly.

I use this tool to generate them, I will not put their URL here because I don't want to spam but you'll find it w/ Google w/o any problem.

The only problem by using this third party software is that I cannot generate random one at each new game, I don't have the skills and knowledge, nor the time too, to dev one for FARC.

So the process is fairly simple, the universe generator of the game do its job, and when a telluric planet is in the process, the generator pause and display all the required data converted for Fractal Terrains, I generate the map in the software by adding only a random seed, put the correct regions' grid and determine the dominant relief and land type that I report into the generator.

As a last process the generator calculates the biosphere and resources and that's it :)

It's simple but a bit tedious and eat some hours by the time to process an entire planetary system. Especially since they are many light & colors sets and many climate textures in the software, and that was all a job to analyze all these files and keep track of whose that I was interested of.

It is possible to generate any kind of surface, even ones for asteroids. I don't do it for them in FARC, because the asteroids are displayed by a basic non textured object and because with the addition of the asteroid belts that could take a VERY long time to generate customized surface map. For reference, Epsilon Eridani have 2 belts and in the game that totalize more than 60 asteroids.

For the grid, it's an in-game thing. In the orbital objects data structure, telluric planets' and asteroids' surface is separated by "regions", used in game to create  a play surface a bit like in Galactic Civilization.

Custom grids can be set into Fractal Terrains, so it facilitate the work greatly.

If you have any other questions, don't hesitate :)