I am working on a project, well, I guess just read the README from the repo (a project which will require a creative rename in the future):

https://github.com/smathermather/shape-pov

shape-pov
ATM, this is a script to write shapefiles to PovRay docs for rendering. Long-term, will be a map tile renderer with 3D support and more.

Whats more? Well, while compositing in TileMill and all the Mapnik derivatives is cool, this tool will handle true material properties, including subsurface scattering, glass like tranparency, diffusion, refraction, and a range of other sophisticated optical effects. The initial focus will be on optical alternatives to compositing rather than 3D.

Stay tuned… .

BTW, will likely be ported from a BASH script to Postgres/PostGIS functions in the future. That and a little middleware glue would provide the interface to the web. This is just the (not yet functional) rapid development version.