Shadows in C

[mberger at RELAY.NSWC.NAVY.MIL]

The spider demo has a shadow capability.

Also, The Iris Universe magazine (winter 1989) has an article title:
   casting shadows on flat surfaces

A paragraph from the article states:
   The easiest way to flatten an object is to use the scal function.  If
   the ground is the plane formed by the x and z axes (y=0) then:
   scale(1.0,0.0,1.0) could be used to create a shadow from a light shining
   straight down the y axis.
If you can't find the article I could FAX it to you.