Elementrix did something similar a few years ago that you might want to check out: http://polycount.com/discussion/105369/new-approach-to-handpainted-environments/p1
Hey. This is going to be a big thread so prepare! I started this project some months ago with the idea of creating a game in a painterly style highly influenced by Poku and league of legends as in how the game is built, pretty much what I want to do is make a game that looks like a painting but is set in a 3D space. Some…