This seems a bit like various volume rendering techniques, except with the objects having no transparency (like they would in a typical tomographic reconstruction)
Maybe we're using different terms or definitions here --- but for me "volume rendering" is a clearly separate domain from "extract spatial information from 2D imagery"..
Extracting the spatial information is a subset of the same problem, I think. Things like tomographic reconstruction use either multiple rays through the same object or parallel rays through the object at different angles, but this gives density through the object and from that the volume and its shape. If you consider the same problem where you have no density or 100% density, you get the spatial information from multiple 2d objects.
I'm not really savvy on the problems though so the math could be totally different and unrelated, but I think you can accomplish the same thing with either method.
See: http://dl.acm.org/citation.cfm?id=378484 and http://en.wikipedia.org/wiki/Tomographic_reconstruction
Very cool for a simple implementation, and considering that the author doesn't appear to have dug deep into existing work.