Removed pyglet
Added OpenGL
Sphere drawing in graphism.visualization.render
Need to generalize viewport and perspective to graph.
Need setter for graph object
Need to iterate over graph to draw spheres in draw_scene
See
bazaar.launchpad.net/~mcfletch/pyopengl-demo/trunk/view/head:/PyOpenGL-Demo/redbook.movelight.py
and rainwarrior.ca/dragon/arcball.zip
for useful example code.