[Edu-sig] Textbooks

Arthur ajsiegel at optonline.net
Sat Feb 25 18:55:50 CET 2006


kirby urner wrote:

>
>     SO:  Any recommendations as to course textbooks?  Or just go with
>     Zelle
>     and/or O'Reilly's latest wood rat book?
>     -   The students presumably have had programming courses already.
>     -   I would think that K-12 students would be happier if they could
>     generate some graphics.
>     -   This is a 6-weeks course.  Little leisure time.
>
>     Appreciate any advice.
>
>     Peter Chase
>     Sul Ross State University
>
>
> I still like Zelle's best and includes some graphics (Tk-based, using 
> his own graphics.py). 
>
> Some of the online tutorials are quite worthwhile as well:
> http://diveintopython.org/ is freely downloadable.
>
> Or roll your own (that's what I've been doing).
>
> Another way to get graphics is to write scene description language 
> (POV-Ray) or even VRML from Python.  I've used this approach 
> successfully, but only because I give students access to prewritten 
> modules.  Like, we might build our own vector class, with a module 
> that already expects to use vectors.
>
> VPython is still more graphically exciting.


My fun this week in some sense involved some synthesis of these 
approaches - having come to a "what is possible" revelation.  

PyGeo uses VPython for vector graphics, and exports to POV-Ray - 
producing a high quality "still" of what one is observing on the screen. 
Except that I hadn't been able to find a way to reliably reproduce a 
representation of a flat plane in POV-Ray that closely resembled the 
PyGeo plane - which is just a mesh of thin lines (the vpytbon curve 
object)- exported to POV-Ray the lines showed too much of their 
thickness, and the illusion of flatness, essential to a plane was lost. 
I realized what *does* work is a image map of a  line mesh - with 
appropriate transparencies - applied to a flat polygon, scaled and 
oriented appropriately in POV-Ray.  But PyGeo allows one to apply any 
color to a plane.  I would lose that in POV-Ray if I used a particular 
image map, or even some collection of them.

Ah-ha.

I now have PIL creating a the image map - transparencies and all - on 
the fly. One can have an unlimited number of plane objects represented 
in an unlimited number of colors created in POV_Ray, pretty reliably 
representing what one is seeing in the on screen rendering. There is 
about 10 lines of easy to follow code involved.

Too much fun.

Art




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