[vtkusers] vtkActor2D / Polygons

Prabhu Ramachandran prabhu at aero.iitm.ernet.in
Fri Dec 8 02:28:57 EST 2000


hi,

>>>>> "DV" == D Vercauteren <dv at mindless.com> writes:

    DV> Hi VTKers, I've tried to change the opacity of an Actor2D with
    DV> no sucess. In a mail found on the list it's explained that
    DV> it's not implemented in vtk2.4. It seems it's not in the
    DV> nightly neither. Is it planned for the upcoming official
    DV> release ? Or is it ok in the nightly and I'm just missing
    DV> something ?

in python the foll. works:

a = vtkActor()
a.GetProperty().SetOpacity (0.5)


    DV> Another one : when building a polygon, if it's convex all
    DV> works fine. If it isn't convex, it seems the triangulate
    DV> method which fills the polygon just pick a point and
    DV> triangulate from it. So the filled polygon has a strange shape
    DV> with triangles overlapping the real one. Is there a way to
    DV> have it work ?  I've tried to pass the polygon through
    DV> vtkTriangleFilter but it's exactly the same problem.

I think the triangulation algorithm requires a convex boundary.  So
concave triangulations wont work, yet.  I am not sure on the status of
this though.

prabhu




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