[vtk-developers] Delaunay2D infinite recursion

[David Gobbi]

Thanks, Will.  I'm not sure if it will be much help, but here is some
of the stack trace.  I make a mistake in my last email, this data set
was giving me infinite recursion in CheckEdge().  However, I have seen
infinite recursion in FindTriangle(), too.

   David


    at /beck/data/dgobbi/Kitware/VTKcvs/Graphics/vtkDelaunay2D.cxx:262
#30831 0x00007f7f3309022a in vtkDelaunay2D::CheckEdge (this=0xa05e40, ptId=7,
    x=0x7fff2b667620, p1=5, p2=19, tri=0)
    at /beck/data/dgobbi/Kitware/VTKcvs/Graphics/vtkDelaunay2D.cxx:263
#30832 0x00007f7f3309022a in vtkDelaunay2D::CheckEdge (this=0xa05e40, ptId=7,
    x=0x7fff2b667620, p1=5, p2=4, tri=17)
    at /beck/data/dgobbi/Kitware/VTKcvs/Graphics/vtkDelaunay2D.cxx:263
#30833 0x00007f7f3309022a in vtkDelaunay2D::CheckEdge (this=0xa05e40, ptId=7,
    x=0x7fff2b667620, p1=5, p2=13, tri=19)
    at /beck/data/dgobbi/Kitware/VTKcvs/Graphics/vtkDelaunay2D.cxx:263
#30834 0x00007f7f330920ce in vtkDelaunay2D::RequestData (this=0xa05e40,
    inputVector=<value optimized out>, outputVector=<value optimized out>)
    at /beck/data/dgobbi/Kitware/VTKcvs/Graphics/vtkDelaunay2D.cxx:524


On Thu, Feb 11, 2010 at 4:18 AM, Will Schroeder
<will.schroeder at kitware.com> wrote:
> David-
> One of these days we are going to have to fix the Delaunay classes properly.
> For such a beautiful algorithm it suffers from insidious numerical issues.
> Either discretize space or use some sort of infinite / higher precision.....
> I'll take a look, it'll likely be this weekend at the earliest.
> Will
>
> On Wed, Feb 10, 2010 at 11:41 PM, David Gobbi <david.gobbi at gmail.com> wrote:
>>
>> Hi All,
>>
>> I've written a clipping filter that uses constrained Delaunay to
>> triangulate the contours that result from the clipping.  The
>> vtkPolygon can triangulate these contours by ear-cut with no
>> difficulty at all, but vtkDelaunay gives me lots of warnings (Edge not
>> recovered, polygon fill suspect) and often crashes.  These contours of
>> mine have no interior points and about 10 unevenly-spaced points on
>> the perimeter.
>>
>> Below is one of the data sets that causes Delaunay2D to crash on my
>> Linux64 gcc-4.2 system.  Specifically,  FindTriangle() goes into
>> infinite recursion.  Can anyone confirm this?  I've also written a
>> python program that displays the problem data and runs delaunay on the
>> data.
>>
>>   David
>>
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> William J. Schroeder, PhD
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