Awhile back, I read about a particular method for making randomized terrain. Different terrain types are given a number, like dirt is 1, grass is 2 and water is 3. Then you randomize certain regions rather than individual tiles. The tiles then get marked as the type it's closest too. The concept I get, and it sounded simple enough to implement but I can't remember what this was called. I was hoping someone would be familiar with the idea and might know the name of it. I want to say it started with a V but I can't be sure.