RE: [Visualpython-users] proposed mesh object

[David S. <dsc...@vy...>]

I wrote:

> I thought about this (in fact, I did it once).  It might not 
> be a bad idea.

I should add this: a "mesh" object like Ari described would be useful
for much more than height fields.  For example, a surface of revolution
or extrusion is also a mesh:

##################

from visual import *

def mesh(pos):
    "Stand-in for mesh object (wireframe rendering)"
    pos = array(pos)
    for i in range(pos.shape[0]):
        curve(pos=pos[i])
    for j in range(pos.shape[1]):
        curve(pos=pos[:,j])

def surface_of_revolution(length, radius):
    circle = arange(0, 2*pi+0.2, 0.2)
    count = len(radius)
    pos = [ [ vector(i*length/count, radius[i]*cos(theta),
radius[i]*sin(theta))
              for theta in circle ]
            for i in range(count)
          ]
    return mesh(pos)

def extrusion( points, displacement ):
    pos = [ (point, point+displacement) for point in points ]
    return mesh(pos)
    
surface_of_revolution( 10, [5,1,1,1,1,2,3,4,5] )

extrusion( [ vector(0,0,0), vector(1,0,0), vector(0,1,0), vector(0,0,0)
], vector(0,0,1) )

###################

mesh would be accessible to more people than faces.  It wouldn't,
however, be as general for people who want to play with new primitives
or *especially* model import.

Dave