[vtkusers] vtkXMLPUnstructuredGridWriter() howto?

[Nico Schlömer]

> So the parallel writer is not there to split the
> data but to write them in parallel when your data are already
> partitioned.

That would perfectly match my expectations.

> And when used with mpi, you can use a filter that split
> and distribute your data among the processes so when they are written
> with this writer, you get a whole set of files.

Unfortunately I have no clue about the concept of filters in VTK.
Until now I would just generate a vtkDoubleArray on each processor and
feed that into the mesh object, which is then written later on. That
said, none of this ever worked, but as we're just exploring there are
other problems too.

I'll try to find the "test/examples files of Parallel VTK kit" Seb
mentioned earlier.

Cheers,
Nico




On Fri, Aug 27, 2010 at 7:39 AM, Sebastien Jourdain
<sebastien.jourdain at kitware.com> wrote:
> Actually, this make sense (in some way). ;-)
>
> The pxxx file is the master file and the 0.xx is the only block where
> the data come from. So the parallel writer is not there to split the
> data but to write them in parallel when your data are already
> partitioned. And when used with mpi, you can use a filter that split
> and distribute your data among the processes so when they are written
> with this writer, you get a whole set of files.
>
> Seb
>
> On Fri, Aug 27, 2010 at 7:19 AM, David Doria <daviddoria+vtk at gmail.com> wrote:
>> On Fri, Aug 27, 2010 at 12:51 AM, Sebastien Jourdain
>> <sebastien.jourdain at kitware.com> wrote:
>>>
>>> ParaView will exactly do that, but on the VTK+MPI side, I don't know
>>> exactly what you should do to make it works. I guess it's all about
>>> setting correctly vtkMultiProcessCommunicator... The number of Piece
>>> should normally be equal to the number of processes, and this might be
>>> automatic in some way. Give a look at the test/examples files of
>>> Parallel VTK kit.
>>>
>>> Seb
>>>
>>
>> Sebastien,
>> I fixed the extent, but still only Test.pvti and Test_0.vti are generated:
>> http://www.vtk.org/Wiki/VTK/Examples/Cxx/Broken/IO/XMLPImageDataWriter
>> The same problem happens with vtkXMLPUnstructuredGridWriter (Test.pvtu and
>> Test_0.vtu) are generated):
>> http://www.vtk.org/Wiki/VTK/Examples/Cxx/Broken/IO/XMLPUnstructuredGridWriter
>> Thoughts?
>> David
>