How does this mod change world generation? Because, I have a modpack (in which this is the only mod that changes world generation) and I want to play on a mountainious map with river, but I am unable to get one using the realistic planets mod. I would really love to be able to keep playing with this mod, because the new biomes are really nice, but I'll have to take it out of the modpack if getting a mountainious map with river is impossible...