[vtkusers] pb w. Delaunay on multiple polygons

[Melvin Hadasht]

Hi Will,

on Mon, 22 Apr 2002 13:39:21 -0400
Will Schroeder <will.schroeder at kitware.com> wrote:


 > If I am reading your script properly, you are using vtkDelaunay2D 
 > incorrectly. The first polygon defines the outer boundary of the polygons; 
 > subsequent polygons in the input define holes in the polygon. You are 
 > placing both polygons in the same source polydata, which doesn't make 
 > sense. 

OK. I thought it was possible to have different polygons (including holes) in
the input of vtkDelaunay2D. And I misunderstood (or read too quickly) the
examples.

 > Instead, you should put each polygon in a separate polydata (include 
 > holes as additional polygons) and triangulate with a separate 
 > vtkDelaunay2D. Or equivalently, set up a pipeline of vtkPolyData and 
 > vtkDelaunay2D, load the polygon (and any holes in the polygon) in the 
 > vtkPolyData, execute the pipeline, save the output, and then repeat the 
 > process. You may have to invoke Modified() on the vtkPolyData every time 
 > you stuff new data into it.

Thanks. I'll try this. The problem is that the polygons come from the outlines
of an arbitrary postscript character glyph. It won't be easy to recognize when a
polygon is completed or not (for example, when the 'a' of a 'ä' ('a' with two
points on its top) is completed to pass it through a pipeline). I guess I have
to work more on this.

Thanks again.

Tionana (Chinyanja, Zambia, Mozambique: See you)


-- 
Melvin Hadasht