2008 SG Interactive Procedural Street Modeling 

The tensor field street generation I talked about previously originally is from this research by Guoning Chen, Gregory Esch, Peter Wonka, Pascal Müller, and Eugene Zhang.

It uses tensor fields, as I discussed last time. You can see how the tensor fields let the generator generalize its knowledge of what direction roads should follow in each region: instead of the user having to hand-draw each route, the tensor field derived from the major roads can smoothly interpolate across the space.

This interpolation in space is one of the things that I find fascinating about generativity being applied to design problems: when we open up the ability to smoothly travel from point to point rather than moving in big, discrete steps, we gain flexibility and expressiveness.

They also use it to build an interactive tool that gives the user instant interactive feedback as the road network is edited. Smart interactive tools are one of the other big things I’m interested in about procedural generation. Tools that help artists by taking care of the minor details while still giving the users control over the direction and goals of the overall project–and feedback when something might go wrong with the current design.