### Example Two: Changing materials

For the code for this example, see Example2.py
Start this example by making a collection of points, v:
`>>> v = ( (0.,0.,0.), (1.,0.,0.),`
`(0.,1.,0.), (1.,1.,0.),`
`(0.,2.,0.), (1.,2.,0.),`
`(0.,3.,0.), (1.,3.,0.),`
`(0.,4.,0.), (1.,4.,0.),`
`(0.,5.,0.), (1.,5.,0.),`
`(0.,6.,0.), (1.,6.,0.))`

and defining some colors:
`>>> RED = (1., 0., 0.)`
`>>> GREEN = (0., 1., 0.)`
`>>> BLUE = (0., 0., 1.)`

and collections of colors:
`>>> col = ( RED, RED, RED, GREEN, GREEN, GREEN, BLUE, BLUE, BLUE, RED, GREEN, BLUE, RED, GREEN )`

`>>> col2 = ( RED, RED, RED, RED, RED, RED, RED, GREEN, GREEN, GREEN, GREEN, GREEN, GREEN, GREEN)`

Define a list to specify the faces of the lines we make later:
`>>> ind = (range(14),)`

Start up a viewer :

`>>> from DejaVu import Viewer`
`>>> vi = Viewer()`

and make a line:

`>>> from DejaVu.IndexedPolylines import IndexedPolylines`
`>>> p = IndexedPolylines('testColor', vertices = v, faces = ind, materials = col)`

and add it to the viewer:
`>>> vi.AddObject(p)`

to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`

and make another line:
`>>> p2 = IndexedPolylines('testColor2', vertices = v, faces = ind,materials = col2)`

and add it to the viewer:

`>>> vi.AddObject(p2)`

to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`

With these two objects in the viewer, try changing the current object and transforming it.

Add another line:
`>>> norm = ((1.0, 0., 0.0 ),) * 14`
`>>> pn = IndexedPolylines('testMaterial', vertices = v, faces = ind,`
`materials = col, vnormals = norm)`
`>>> vi.AddObject(pn)`

to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`

Add another line:
`>>> pn2col = IndexedPolylines('testMaterial2', vertices = v, faces =ind,`
`materials =col2,vnormals = norm)```

`>>> vi.AddObject(pn2col)`
to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`

Finally, try making some rows of spheres colored differently:
`>>> from DejaVu.Spheres import Spheres`
`>>> s1 = Spheres('test', centers = v, radii = (0.4,), materials = col, quality=15)`
`>>> vi.AddObject(s1)`
to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`

`Add another set of spheres, colored differently with default quality.`
`>>> s2 = Spheres('test7', centers = v, radii = (0.4,), materials = col2)`
`>>> vi.AddObject(s2)`
to see the new object, we have to redraw the scene:
`>>> vi.Redraw()`