[vtkusers] get unstructured grid from vtkXdmf3Reader

[David E DeMarle]

Hi Nico,

That is for multi-block xdmf files. If you happen to have a file with
several blocks in it it will return the correct number (try IronProtein
from the paraview regression test data). Probably a bug that it reports 0
when you have a single atomic ("uniform" in xdmf terms of "vtkDataSet" in
vtk terms) grid.

I don't happen to have a small example of its use in VTK. In ParaView it is
used in the Block selection part of the object inspector when you open the
xdmf file.

hth





David E DeMarle
Kitware, Inc.
R&D Engineer
21 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-881-4909

On Tue, Jun 16, 2015 at 9:04 AM, Nico Schlömer <nico.schloemer at gmail.com>
wrote:

> Apparently,
> ```
>  xreader->GetNumberOfGrids()
> ```
> doesn't say much. One can simply
> ```
>   vtkDataObject *rOutput = xreader->GetOutputDataObject(0);
>   TEUCHOS_ASSERT(rOutput != nullptr);
>   vtkUnstructuredGrid * m = dynamic_cast<vtkUnstructuredGrid*>(rOutput);
>   TEUCHOS_ASSERT(m != nullptr);
> ```
> which gives you a pointer to the vtkUnstructuredGrid, if there is one.
>
> Cheers,
> Nico
>
> On Tue, Jun 16, 2015 at 1:46 PM, Nico Schlömer <nico.schloemer at gmail.com>
> wrote:
> > Hi everyone,
> >
> > I have an XDMF file which I'm reading with vtk::vtkXdmf3Reader,
> > ```
> >   vtkXdmf3Reader *xreader = vtkXdmf3Reader::New();
> >   xreader->SetFileName("data/brick-w-hole.xmf");
> >   xreader->Update();
> > ```
> > and I would like to get the corresponding vtk::UnstructuredGrid from
> > this. For some reason, however,
> > ```
> >  xreader->GetNumberOfGrids()
> > ```
> > returns 0. Also, I wouldn't know how to retrieve the grid if there was
> one.
> >
> > Is there example code for this around?
> >
> > Cheers,
> > Nico
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
>
> Search the list archives at: http://markmail.org/search/?q=vtkusers
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/vtkusers
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20150618/4f4235b7/attachment.html>