Some python code to back project a 3D volume from a series of shadows.
3d_projection.py contains the good stuff. selection_plot.py is a quick
app to let you define a polygon from an image file.
Here is an example of the point cloud volume produced by this algorithm (cross eyes to view in stereo 3D):
This cloud was generated using the polygons in the input directory
You can find a more detailed writup on my blog: http://jack.minardi.org/software/whats-in-a-shadow/