[Visualpython-users] [Q] Need help on extending VPython

[Young-Jin L. <yl...@ui...>]

Hi, I was looking for some help for the problem I got while I was trying to
extend VPython little bit.
I wanted to assign some properties on the VPython object. For instance, I
want to give a VPython sphere object a particular name. By assigning a
unique name on the VPython object, I will be able to do bookkeeping them
using a dictionary. Here is what I tried.

from visual import *

class Ball:
    def __init__( self, name, color ):
        self.sphere = sphere( color = color )
        self.name = name;

    def clickOn( self ):
        print self.name

scene.range = 4
components = {}
ball1 = Ball( "Ball 1", (0, 1, 0) )
components[ ball1.sphere ] = ball1

while 1:
    if scene.mouse.clicked:
        m = scene.mouse.getclick()

        #scene.mouse.pick.color = (0, 0, 1)
        global components
        b = components.get( scene.mouse.pick )
        if b:
            print "1"
            print b.clickOn()
            print "2"

        loc = m.pos
        #print loc
        sphere( pos = loc, radius = 0.1, color = (1,0,0) )

I created one sphere object and assigned the only property, the name, and
put it into the global dictionary. Then when I get a mouse click, I examined
the clicked object, checked the global dictionary, and if it is the case,
print out the name of it.
When I ran this test script, I expected to get "1\nBall 1\n2", but I got
"1\nBall 1\nNone\n2". I have no idea where "None" came from.

Is there anybody who can help me with this problem? Is this the right way of
extending VPython?
Any comment on any of above questions will be greatly appreciated.

TIA.

YJ