[vtkusers] unstructured grid + tetrahedrons

[Bill Lorensen]

If I recall correctly, for UnstructuredGrids, DataSetMapper calls
DataSetSurfaceFilter which extracts the external faces for display.
This is done automatically.

Bill

On Thu, Dec 10, 2009 at 8:22 AM, Jérôme <jerome.velut at gmail.com> wrote:
> Hi,
> A vtkDatasetMapper is a generic mapper that, according to its name, maps
> vtkDataSet. You will find that vtkImageData, vtkPolyData,
> vtkUnstructuredGrid and a lot of other vtk data structures inherit from
> vtkDataSet. Basically, it means that vtkDataSetMapper will 'see' a volume
> (vtkImageData) like a mesh ('vtkPolyData') but also like a volumic mesh
> ('vtkUnstructuredGrid'). For instance, try to map a volume (mhd, dicom or
> vti) through a DataSetMapper: you will render only the grid of the external
> faces! (yes, try it, because I only assume that!).
>
> By reading the doc, I saw that DataSetMapper has a vtkPolyDataMapper as
> member. It makes me thinking that this mapper maps *everything* has it was a
> polydata (*maybe* building explicit topology when it has to). And a polydata
> has no 3D cells such as in vtkUnstructuredGrid. This *could* explain the
> behaviour you described.
>
> How can you see the tetrahedron? By using a vtkUnstructuredGripVolumeMapper,
> but my knowledge stop here!
>
> HTH
> Jerome
>
>
>
> 2009/12/10 Baliki B. <balikivtk at gmail.com>
>>
>> Hi,
>>
>> i have an unstructured grid (a file) which contains tetrahedrons.
>> I read the file with vtkUnstructuredGridReader.
>> Then i use a vtkDataSetMapper but i  don't really get the tetrahedron but
>> the boundary tringles.
>>
>> What am i doing wrong?
>> How can i visualize it so that i can see the tetrahedrons?
>>
>> (Sorry if my questions are "stupid".)
>>
>>
>>
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