[Paraview] How to create a parallele reader for paraview ?

[Moreland, Kenneth]

Seb,

It sounds like you have a pretty good grasp of how parallel readers work
in VTK/ParaView.  A reader is expected to respond to the "extent"
request that comes from the pipeline, which I think is what you mean by
the "streaming API."  It is used to both specify pieces that are
streamed in as well as specify pieces per process in a data parallel
mode (such as used in ParaView).

I cannot think of a reader that works exactly as you describe, but there
are some that do use a vtkMuliProcessController (vtkSpyPlotReader is
one).  You can get a controller with
vtkMultiProcessController::GetGlobalController().  ParaView will
initialize this global controller with the MPI controller that contains
MPI_COMM_WORLD.

Does that answer your question?

-Ken

> -----Original Message-----
> From: paraview-bounces+kmorel=sandia.gov at paraview.org
[mailto:paraview-
> bounces+kmorel=sandia.gov at paraview.org] On Behalf Of Sebastien
Jourdain
> Sent: Thursday, January 17, 2008 2:53 AM
> To: paraview at paraview.org
> Subject: [Paraview] How to create a parallele reader for paraview ?
> 
> Hello,
> 
> I would like to create a parallele reader that could be used in a
> standard manner by paraview.
> 
> My problem, is that I'm not sure how paraview manage it's pipeline
> distribution. (when it's deployed in MPI over a cluster)
> 
> I think, (please correct me if I'm wrong)
> that paraview 3 use the VTK 5 streaming API for the standard reader to
> split input data among each MPI process by selecting on piece for each
> MPI process and by simply applying the processing pipeline behind each
> selected piece.
> Or if the distribution is not made by the reader, the
> vtkDistributedDataFilter is used.
> 
> The thing is, I don't want each reader to read the file. I need only
one
> master reader that will generate n dataset for the n processes. And by
> now, I don't know how to manage this distribution to allow paraview to
> add the processing pipeline behind each distributed dataset in a
> standard manner. I wanted to use the vtkTransmitXXXPiece classes to
> forward each piece to each process but I can't find any sample on how
to
> make it work with paraview.
> 
> If someone has exemples or informations I would really apreciate,
> 
> Thanks,
> 
> Seb
> 
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