I would like to manipulate a 3D skeleton. On the opengl list, it was
suggested povray would be easier to learn, and perhaps more powerful
than opengl.

I did find rupov There are recent books on opengl, but I don't find any
book on pov-ray and I don't see any example of the use of pov-ray with
ruby. I did not find a library of opengl commands either. How do people
figure out how to use pov-ray or opengl for ruby?

I have installed opengl for ruby opengl-0.32g, and the examples compile
fine in that directory, but
not in other directories? What could have gone wrong in the install of
opengl for ruby?

I used a modified extconf as per instructions elsewhere
$ ruby extconf.rb
$ make

Test it out works, as well as all other examples in the sample
directory
$ ruby sample/robot.rb

Install it:
$ sudo make install

I did not try to install rupov, I don't know if it works on Tiger or
what to do to install it.