This is the tutorial that was in the July 1993 issue of AMAZING COMPUTING.

Of course, I modified it slightly by adding a ground surface.  I did not
include the GRANITE.RGB file since it is not public domain, it is the
texture from another program (read not freely distributable).

I know this is not very original but, it may help people that don't
want to take the time to set this up and just jump into the rendering
aspect.

Hope you enjoy it.

Bob Donlon
Atlantis Video Productions
42 Grissom Drive
Clifton Park, New York 12065