[vtkusers] delaunay3d: degenerate triangles encountered

[John Harris]

or maybe its something to do with the normals, I wonder if there is any test 
that I can do to figure out the problem?
thanks again  :s
JH

>From: "John Harris" <lost_bits1110 at hotmail.com>
>To: vtkusers at vtk.org
>Subject: Re: [vtkusers] delaunay3d: degenerate triangles encountered
>Date: Tue, 16 Aug 2005 15:01:23 +0000
>
>... so do you think that the problem is the way I read in my mesh? i.e. the 
>way I create my vtkUnstructuredGrid??
>Are there any filters I should use that could prevent the problems I'm 
>getting? :s
>Any suggestions are appreciated,
>Thanks again..
>JH
>
>
>>Subject: Re: [vtkusers] delaunay3d: degenerate triangles encountered
>>
>>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?
>>><< signature.asc >>
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>>
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