I'm looking for a full-featured application for making entire sphere-like worlds. Bonus points if it can also handle some of the physics for how two planetary bodies very near each other would interact. I have Fractal Terrains 3, which is nice to get the basic geography of a single planet, but it does not have the abilities to populate said planet with plants and/or animals, export in a file type easily usable by other applications, nor can it simulate what would happen if I put two worlds very close to each other. I understand that finding a single application that can do all of this is unlikely, but if it could at least do a lot of the above it would be nice.
Its a 3d graphics editor and can edit animate render export etc. with a built in game maker you can achieve what you want.
And the Random World