No code here, but other technical details and some photos of what's possible in this paper http://www.cl.cam.ac.uk/~mgk25/ih98-tempest.pdf http://www.cl.cam.ac.

No code here, but other technical details and some photos of what's possible in this paper http://www.cl.cam.ac.uk/~mgk25/ih98-tempest.pdf http://www.cl.cam.ac.uk/~mgk25/ih98-tempest.pdf - possibly the one you were thinking of in your parallel comment.