There is another attempt for cartoon like povray renders -
http://www-inst.eecs.berkeley.edu/~dtw/pov/misc/_povsrc/ .
Look after outline1.pov to outline3.pov.
Its similar to Thibaut's object-based toon shading approach IIRC.
David Wallace did some other very nice images too -
http://www.ocf.berkeley.edu/~dtw/3D_Graphics/index.html .
Norbert Kern
