At 02:06 PM 02/18/2000 -0500, Arthur Siegel wrote:

It allows one to create relationships in 3d space between geometric "primitives" -points,lines,circles, spheres,etc. - by way of simple Python scripts. Points on the initial figure created can then be picked and moved, but all defined relationships follow. It's more sophisticated functions - the uses of arrays of points and lines for example, can be used to explore concepts of Projective Geometry in 3d space.

Sounds very interesting Arthur. My approach has been to keep things simple in Python by having it write scripts intelligible to other programs which already know tons about 3D graphics. Students write simple Python commands and get .wrl or .pov files out the back, which then go to a VRML viewer (usually a web browser plug-in) or to POV-ray, a free, full-featured ray tracing engine. This approach typifies what Python is good for: acting as a "glue language" in collaboration with more specialized apps. What I give up, by going this route, is any trully "dynamic" interface, i.e. students can't just grab stuff with a mouse and twirl it in real time, or add edges/vertices by simply pointing and clicking (as they can in STRUCK, freeware written by my colleague, Gerald de Jong, in Java). I presume because of your OpenGL add-in etc., that you're somehow making Python do graphical updates in real time, in response to user-generated events. Personally, I don't know Tk well enough to know how this is done. Seeing your program would probably teach me a lot. At this point in time, I'd be most interested in seeing screen shots though, since I don't feel ready to digest complicated source code. I'd like to develop an under- standing the gist of your technique (without trying to comprehend an entire application). If you want to share any "cave painting" snippets that give me a feel for your strategy, I bet others besides me would be interested. Mostly, what I'm wondering is whether students with a modest grasp of Python would be able to abstract generic strategies and techniques from your tools -- what I'm trying to impart at my Oregon Curriculum Network, where all my source code is freely available and dissected in some detail for the benefit of Oregonians (and other lurkers). Kirby Curriculum writer Oregon Curriculum Network