VPython tutorial

2,
3D Objects
create 3 balls with vectors sticked on it and pointing toward a certain direction

from visual import*

##3 balls

sphere(pos=vector(0,-5,0),raduis=1,color=color.green)
arrow(pos=vector(0,-5,0),axis=vector(+3,+3,0),color=color.red)

sphere(pos=vector(5,5,0),raduis=1,color=color.green)
arrow(pos=vector(5,5,0),axis=vector(-5,0,0),color=color.red)

sphere(pos=vector(-5,5,0),raduis=1,color=color.green)
arrow(pos=vector(-5,5,0),axis=vector(0,-3,0),color=color.red)

4. after watching variable assignment, create 3 balls with vectors connecting  balls

from visual import*

##vectors2

b=sphere(pos=vector(0,-10,0),raduis=3,color=color.green)
c=sphere(pos=vector(5,5,0),raduis=3,color=color.green)
a=sphere(pos=vector(-5,5,0),raduis=3,color=color.green)


arrow(pos=b.pos,axis=c.pos-b.pos,color=color.red)
arrow(pos=c.pos,axis=a.pos-c.pos,color=color.red)
arrow(pos=a.pos,axis=b.pos-a.pos,color=color.red)

4. **move one sphere twice as far from the y-axis.

4.1 Print command

from visual import*

b=sphere(pos=vector(0,-10,0),raduis=5,color=color.green)

c=sphere(pos=vector(5,5,0),raduis=5,color=color.green)

a=sphere(pos=vector(-5,5,0),raduis=5,color=color.green)

arrow(pos=b.pos,axis=c.pos-b.pos,color=color.red)

arrow(pos=c.pos,axis=a.pos-c.pos,color=color.red)

arrow(pos=a.pos,axis=b.pos-a.pos,color=color.red)

print(a.pos) 

The following lines show in the shell:

Python 2.7.9 (default, Dec 10 2014, 12:28:03) [MSC v.1500 64 bit (AMD64)] on win32

Type "copyright", "credits" or "license()" for more information.

>>> ================================ RESTART ================================

>>> 

>>> ================================ RESTART ================================

>>> 

>>> ================================ RESTART ================================

>>> 

<-5, 5, 0>