How would one make a planet mod?

[DerpenWolf]

I'm not sure if this is the best place to ask this but I don't really see anywhere better so here it is.

So I've seen a few planet mods around and I vaguely recall that their was some mod that allowed the easier implementation of such things. If anyone could help me by sending me links to any such things as well as info on how I might go about doing this as well as height-map/texture stuff for the planets I would be very grateful.

[Vanamonde]

Modding question? Why not ask it the luxurious General Add-on Affairs sub-forum? Now with pine-scent! (Moved.)

[Xaiier]

Kopernicus is a new mod in development that is set to make planet adding a much easier task:

http://forum.kerbalspaceprogram.com/threads/88168

Krag's Planet Factory CE was the old mod that would allow you to do such things, but it's no longer being updated:

http://forum.kerbalspaceprogram.com/threads/65401

Outside of using those, you would have to make your own system or implement the systems they have used to make it work, which is how things like RSS, Alternis Kerbol, etc worked.