[Visualpython-users] incorrect convex objects?

[Cettinich E. (LWE) <edw...@lw...>]

Because extrusion objects are not supported in VPython I=20
create them as a set of convex objects. I found, that some=20
of them are not drawn correctly.
For instance, please try this code:

from visual import *
d1=3Dconvex(pos=3D[( 0, 0, 0), ( 0, 1, 0), (-1, 1, 0)])
d2=3Dconvex(pos=3D[(-1, 1,-1), ( 0, 1,-1), ( 0, 0,-1)])
m0=3Dconvex(pos=3D[( 0, 0, 0), ( 0, 0,-1), ( 0, 1,-1), ( 0, 1, 0)])
m1=3Dconvex(pos=3D[( 0, 1, 0), ( 0, 1,-1), (-1, 1,-1), (-1, 1, 0)])
m2=3Dconvex(pos=3D[(-1, 1, 0), (-1, 1,-1), ( 0, 0,-1), ( 0, 0, 0)])

and watch m2. It is not drawn as rectangle, instead I can=20
only see the triangle [(-1, 1, 0), (-1, 1,-1), ( 0, 0,-1)].=20

Rotate and shift left m2's pointlist in the above code like this:
    m2=3Dconvex(pos=3D[(-1, 1,-1), ( 0, 0,-1), ( 0, 0, 0), (-1, 1, 0)])

Now m2 is fully drawn as a rectangle.

Does anyone know what's wrong and how to get a correct convex object?

I don't have any idea if there is something wrong and I see only 2 workarou=
nds:
1.) I may create a rectangle in the XY-plane and rotate it appropriately, o=
r
2.) I may split the rectangle into triangles.


Thanks in advance for any answer,
Edwin Cettinich