Take a peek at all of the author's projects [1]. It's amazing, humbling, depressing...
If you are into games, a solution to interactive picture generation by artists would be akin to a particle editor. You let them define a few parameters and valid ranges, then the artist supplies graphics in the right places: voila. A good looking animation. Now restrict the end user to a few well defined ranges of these parameters as well and you have an interactive picture.