Quote from BadW0lf
On SMP, WorldEdit can do //regen which will regenerate the area selected.
I need to generate new terrain, not return changed terrain back to its original form. I don't want to override currently existing terrain either, I want it to not stop generating terrain where it cuts off now, to continue outward to some defined limit. There's a mod which doubles "far"'s draw distance, but I would preferably want it out of game, and even bigger than that, on a whole world scale (Yes I know this could take awhile depending on the size of the world)