[Paraview] Problems reading distributed data

[Benjamin Ahrenholz]

Hi Everybody,

after reading the Paraview guide and other sources I am still not able to
load parallel written image data (pvti) into ParaView. 
First the pvti file:

<?xml version="1.0"?>
<VTKFile type="PImageData" version="0.1" byte_order="LittleEndian">
  <PImageData WholeExtent="    0   50    0   50    0   50" Origin="0 0 0"
Spacing="1 1 1">
    <PPointData>
    </PPointData>
    <PCellData>
      <PDataArray type="Float32" Name="pressure"/>
      <PDataArray type="Float32" Name="phase"/>
      <PDataArray type="Float32" Name="velocity" NumberOfComponents="3"/>
    </PCellData>
    <Piece Extent="    0   25    0   25    0   50"
Source="bubble.test1.0000.pt.00000000.vti"/>
    <Piece Extent="    0   25   25   50    0   50"
Source="bubble.test1.0001.pt.00000000.vti"/>
    <Piece Extent="   25   50    0   25    0   50"
Source="bubble.test1.0002.pt.00000000.vti"/>
    <Piece Extent="   25   50   25   50    0   50"
Source="bubble.test1.0003.pt.00000000.vti"/>
  </PImageData>
</VTKFile>

The pieces are distributed to _local_ diskspace on _different_ nodes, which
means:

	<Piece Extent="    0   25    0   25    0   50"
Source="bubble.test1.0000.pt.00000000.vti"/>
	<Piece Extent="    0   25   25   50    0   50"
Source="bubble.test1.0001.pt.00000000.vti"/>

are on, lets say, node1 and

	<Piece Extent="   25   50    0   25    0   50"
Source="bubble.test1.0002.pt.00000000.vti"/>
	<Piece Extent="   25   50   25   50    0   50"
Source="bubble.test1.0003.pt.00000000.vti"/>

are on node2. Additionally the .pvti file is located in the same directory
on both nodes. After starting ParaView in parallel on both nodes (dataserver
and renderserver, pvclient on the masternode - which is by the way working
fine...) the dataserver issues error messages about missing pieces and it's
extents, e.g.:

Process id: 2 >> ERROR: In
/scratch/paraview_cvs/ParaView/VTK/IO/vtkXMLPStructuredDataReader.cxx, line
450
vtkXMLPImageDataReader (0x36ff010): No available piece provides data for the
following extents:
    0 25  0 25  25 50
The UpdateExtent cannot be filled.

The question now is how to tell ParaView where to look for the right pieces?
Our cluster file system is very slow, so that dumping all data into a single
folder is unfortunatly not an option. I tried different data files and e.g.
Polydata (.pvtp) seem not to care about extends (of course) and are loaded
from different nodes without complains. 

Has anybody an answer to that issue? I would be very thankful!

Cheers,

Benjamin
____________________________________

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Modeling in Civil Engineering
Technical University of Braunschweig
 
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