Hello!
For prisms (and lathes) I have found the open source drawing program
Inkscape (http://www.inkscape.org/) to be invaluable - it's very easy to
manipulate curves, and then you can export the drawing as a POV-Ray bezier
spline. All you need to do is cut and paste the object definition into your
scene, or #include the saved file.
Hope that helps
Bill
