[Animats]

There are lots of programs which generate a semi-plausible city map, perhaps filled with generic buildings. But so far nobody seem to be able to generate something that looks even vaguely convincing from street level.

It would be fun, and even useful, to have a procedural storefront generator. One that constructs storefront styles, signage styles, door styles, and window displays. Use images from a street view program to train a machine learning algorithm as to what various parts of cities look like. Don't just use existing storefront images; build them up in 3D from door, window, sign, and display components.