[vtkusers] apply vtktubes to unstructured mesh

[Jérôme]

Hi,

The local orientation of the cylinder is computed from a local chart
(Frenet-serret frame) along a curve, that is a topological constraint. It
has to handle with curvature sign changes in order to keep a consistent
meshing, thus the neighbours of a point (topology) have to be known. The
reason why vtkTubeFilter derives from vtkPolyDataAlgorithm is, IMHO, that
the GetLines( ) function ensures that the filter will deal with 1D
topological cells.

It should not be too difficult to write a filter that converts an
unstructured grid to a polydata in which you get the input cell's type and
add polylines to the output when matching cells are found.

Jerome

2010/1/28 pablo p del castillo <pablodecastillo at yahoo.es>

>  It seems better write scalar to create subdomains depending of the number
> of nodes per cell, and then with vtkThreshold select lines.
>
> But it is strange that vtk has tools to extract edges, but not to select
> diferent cells based in their shape.
>
> I am newbie in vtk.
>
> Pablo
>
> --- El *mié, 27/1/10, David Doria <daviddoria+vtk at gmail.com<daviddoria%2Bvtk at gmail.com>
> >* escribió:
>
>
> De: David Doria <daviddoria+vtk at gmail.com <daviddoria%2Bvtk at gmail.com>>
> Asunto: Re: [vtkusers] apply vtktubes to unstructured mesh
> Para:
> CC: "vtkusers at vtk.org" <vtkusers at vtk.org>
> Fecha: miércoles, 27 de enero, 2010 14:05
>
>
> On Wed, Jan 27, 2010 at 6:50 AM, pablo p del castillo <
> pablodecastillo at yahoo.es <http://mc/compose?to=pablodecastillo@yahoo.es>>wrote:
>
>>  Hello,
>>
>> I have a unstructured mesh with triangles and lines, how can i extract
>> lines to apply tubes.
>>
>> Advanced thanks
>>
>>
>>
> Hmm, is there any reason why vtkTubeFilter derives from
> vtkPolyDataAlgorithm? It seems like if it could derive from
> vtkPointSetAlgorithm instead this question would be no problem.
>
> Pablo, if you can get your lines into a vtkPolyData, you can use this
> method to get tubes on your lines:
> http://www.cmake.org/Wiki/VTK/Examples/TubeFilter
>
> Thanks,
>
> David
>
> -----Adjunto en línea a continuación-----
>
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