[vtkusers] delaunay3d: degenerate triangles encountered

[John Harris]

Thanks all for your responses,

My data is actually from an unstructured grid which is composed of 
tetrahedra, I then use GeometryFilter to convert the tetrahedra to triangles

Acutally here is my pipeline:

	GeometryFilter
	DecimatePro
	PolyDataNormals
	Delaunay3D

My tolerance is also positive and is set to 0.01.

I even tried passing my decimate object through vtkSmoothPolyDataFilter 
first as someone had suggested in a previous post, but this doesnt solve the 
problem.

So not only do I get degenerate triangles, but sometimes my program will 
crash due to " *** glibc detected *** double free or corruption: "

Here is my exact code:

	GeometryFilter->SetInput( Ugrid );
	DecimatePro->SetInput( GeometryFilter->GetOutput() );
	DecimatePro->SetTargetReduction( 0.9 );
	DecimatePro->PreserveTopologyOn();

	PolyDataNormals>SetInput( DecimatePro->GetOutput() );
	PolyDataNormals->ConsistencyOn();
	PolyDataNormals->AutoOrientNormalsOn();

	Delaunay3D->SetInput( PolyDataNormals->GetOutput() );
	Delaunay3D->SetTolerance (0.01);
	Delaunay3D->SetAlpha(0.0);
	Delaunay3D->BoundingTriangulationOff();
	Delaunay3D->Update();
	Delaunay3D->Modified();

If anyone has any insight that would be great!!
Thank you!!
JH


>From: "Kevin H. Hobbs" <kevin.hobbs.1 at ohiou.edu>
>Reply-To: hobbsk at ohiou.edu
>To: Amy Squillacote <amy.squillacote at kitware.com>
>CC: vtkusers at vtk.org, John Harris <lost_bits1110 at hotmail.com>
>Subject: Re: [vtkusers] delaunay3d: degenerate triangles encountered
>Date: Mon, 15 Aug 2005 12:04:30 -0400
>
>On Mon, 2005-08-15 at 08:47 -0400, Amy Squillacote wrote:
> > The error message is being produced by vtkDelaunay3D.  It probably
> > means you have "triangles" in your data set where at least two of the
> > points in a single triangle are coincident.
> >
> > - Amy
>
>I just got the same error with a positive tolerance. The tolerance
>parameter should discard coincident points.
>
>My data are from a regular lattice and so fit the warning in the
>doxygen.  Are yours?
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