[Paraview] Segmentation Fault when using the vtkPVDReader

[Bogdan Daqui Herrera]

Hello all,

I am attempting to write some code in c++ which uses the vtkPVDReader from the paraview library to read a series of vtm files. However I am encountering some
problems and I am not sure whether there is something I am missing or whether this could be a bug.

I am trying to use the reader in the following manner:
My Code:
	vtkSmartPointer <vtkPVDReader> pReader = vtkPVDReader::New();
	pReader->SetForceOutputTypeToMultiBlock(1);
	pReader->SetFileName("/some/fileName.pvd");
	pReader->Update();
	vtkMultiBlockDataSet* pMultiBlockDataSet->DeepCopy(vtkMultiBlockDataSet::SafeDownCast(pReader->GetOutputDataObject(0)));

Error:
	The error occurs at Update() with the following result:
	ERROR: In /misc/dn47/SALOME/PRODUCTS/7x/opt/Ubuntu.13.10.64/7.4.0/tmp/ParaView-4.1.0_SRC/ParaViewCore/VTKExtensions/Default
	/vtkXMLCollectionReader.cxx, line 316
	vtkPVDReader (0x224d9e0): Error creating "vtkXMLMultiBlockDataReader" using vtkPVInstantiator.
	Segmentation fault

Possible error Source
The code concerning line 316 from vtkXMLCollectionReader.cxx is:

      // Use the instantiator to create the reader.
      vtkObject* o = vtkPVInstantiator::CreateInstance(rname);
      vtkXMLReader* reader = vtkXMLReader::SafeDownCast(o);
      this->Internal->Readers[index] = reader;
      if(reader)
        {
        reader->Delete();
        }
      else
        {
        // The class was not registered with the instantiator.
        vtkErrorMacro("Error creating \"" << rname
                      << "\" using vtkPVInstantiator.");
        if(o)
          {
          o->Delete();
          }
        }
      }

I have isolated the following lines and tested them independently:
      vtkObject* o = vtkPVInstantiator::CreateInstance(rname);
      vtkXMLReader* reader = vtkXMLReader::SafeDownCast(o);

The pointer "vtkObject* o" is NULL regardless of the class name I pass to instantiate, and I can imagine something like that happening in the library, too and
causing the segmentation fault, when calling a SafeDownCast(o) (which is NULL).


Any suggestions on how to deal with this problem or if you would be so kind to point me to an example for an alternative solution (Could be vtkFileSeriesReader,
but this fails, as well in my case) would be appreciated.

Kind Regards,
Bogdan

P.S.: Using the PVDReader from python code works flawlessly, which is also quite confusing, as to why it would fail in the C++ code.

-- 
Bogdan Daqui
Software Development

SimScale GmbH
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Phone: +49 (0)89 3398 4078
Email: bdaqui at simscale.de

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