20nov15
Even more disappointing is that vspiral.py, which still worked in 2005
has ceased to work with the lastest revisions. The other, spiral.py, is
a translation for vspiral.py from visual to OpenGL. But it also has an 
out of range error now. This pair should be repaired to work with current
versions of VPython.


GF1nov15
Checking this out in vpy probably version 6 (2013) on mac OS 10 is 
disappointing. Many interesting features Baker put into the vpy examples
no long work correctly.

light.py works, Sun(light source)-earth-moon
earth.py works, sun-eath-moon but illogically lighted
earth_frames.py shows how to use frames in earth.py 
         Study of these goes a long way for particle system apps.


blobby.py  partially working. 
bloxy.py   ditto 
         Still good for seeing how to build an articulated animation
         but the pick-drag 
Since these examples used pre-Version 5(2008) we have a version incompat.
Note, the same is true for Emily Echaverria's 2006 vpy Horsewalk. 
There is a working version Chung seems to have revived with his FramesSJC
project in 2011. So there's hope, to revive pick/drag too. 


gf2oct12
Winmerge reveals that blobby.py and bloxy.py differ only on the 
alleged mouse button choice. 
earth.py and earth_frames.py compared in bakerEarthFrames.png


gf18apr05
and 2oct09 continued 20oct09 and 17nov09 

This table of contents is arranged approximately the way William Baker
intended these lessons to be studied. He uses three different graphics 
libraries wrapped in python. 

The first group uses visual.py from VPython. It begins with some experiments
with a planetary system and lighting. The final example is an articulated
blobby man in the manner of Jim Blinn, written in the scene-graph language
of VPython, where the word "frames" is used. 

frame-doc  rudimentary documentation for using frames
light.py  visual.py app use /sw/bin/python2.4 which has visual on its path
earth.py   visual.py app
earth_frames.py  modification of earth.py to show the use of frames 

blobby-readme  documentation for the following 
blobby.py  is a visual.py application and uses mouse buttons
               for picking and moving of joints.   

The second group are some examples using the two-dimensional graphics
package TkInter.

sierp.py  with TkInter
sine_final.py  with TkInter,  looks good running
SPIRALREADME

The OpenGL examples have problems that could be solved, but should just
yield to the tutorials in Stan Blank's, PyOpenGL.pdf notes.

spiral.py is an OpenGL app and in 10.5 python is throws Error 1002 now
spiral.py does funny things with --i 3 --p 0 ? 
          maybe there should be default values or a usage 
          statement.
vspiral.py  is a visual.py application and still works