ParaView/Examples/Plugins/Reader

This example shows how to turn a custom VTK reader into a ParaView Reader filter. In this example we do not actually read a file, but instead generate data (so this is really a source, not a reader, but this is simply to make it easier to try the example - the structure is setup as a reader). That is, once you load the plugin in ParaView, you must go to File -> Open and select a ".abc" file (the file can be empty). This is the file that would be read if the reader actually did some reading! You should see a single point/vertex in the resulting PolyData object.

MyReader.h

<source lang="cpp">

1. ifndef __MyReader_h
2. define __MyReader_h

1. include "vtkPolyDataAlgorithm.h"

class MyReader : public vtkPolyDataAlgorithm { public:

 vtkTypeMacro(MyReader,vtkPolyDataAlgorithm);
 void PrintSelf(ostream& os, vtkIndent indent);

 static MyReader *New();

 // Description:
 // Specify file name of the .abc file.
 vtkSetStringMacro(FileName);
 vtkGetStringMacro(FileName);
 

protected:

 MyReader();
 ~MyReader(){}

 int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);

private:

 MyReader(const MyReader&);  // Not implemented.
 void operator=(const MyReader&);  // Not implemented.

 char* FileName;

};

1. endif

</source>

MyReader.cxx

<source lang="cpp">

1. include "MyReader.h"

1. include "vtkObjectFactory.h"
2. include "vtkStreamingDemandDrivenPipeline.h"
3. include "vtkInformationVector.h"
4. include "vtkInformation.h"
5. include "vtkDataObject.h"
6. include "vtkSmartPointer.h"
7. include "vtkVertexGlyphFilter.h"

vtkStandardNewMacro(MyReader);

MyReader::MyReader() {

 this->FileName = NULL;
 this->SetNumberOfInputPorts(0);
 this->SetNumberOfOutputPorts(1);

}

int MyReader::RequestData(

 vtkInformation *vtkNotUsed(request),
 vtkInformationVector **vtkNotUsed(inputVector),
 vtkInformationVector *outputVector)

{

 // get the info object
 vtkInformation *outInfo = outputVector->GetInformationObject(0);

 // get the ouptut
  vtkPolyData *output = vtkPolyData::SafeDownCast(
           outInfo->Get(vtkDataObject::DATA_OBJECT()));

 // Here is where you would read the data from the file. In this example,
 // we simply create a point.

 vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New();
 vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
 points->InsertNextPoint(0.0, 0.0, 0.0);
 polydata->SetPoints(points);

 vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
   vtkSmartPointer<vtkVertexGlyphFilter>::New();
 glyphFilter->SetInputConnection(polydata->GetProducerPort());
 glyphFilter->Update();

 output->ShallowCopy(glyphFilter->GetOutput());

 return 1;

}

void MyReader::PrintSelf(ostream& os, vtkIndent indent) {

 this->Superclass::PrintSelf(os,indent);

 os << indent << "File Name: "
     << (this->FileName ? this->FileName : "(none)") << "\n";

}

</source>

MyReader.xml

<source lang="xml"> <ServerManagerConfiguration>

 <ProxyGroup name="sources">
   <SourceProxy name="MyReader" class="MyReader" label="MyReader">
     <Documentation
        long_help="Read a .abc file."
        short_help="Read a .abc file.">
     </Documentation>
     <StringVectorProperty
           name="FileName"
           animateable="0"
           command="SetFileName"
           number_of_elements="1">
       <FileListDomain name="files"/>
       <Documentation>
         This property specifies the file name for the PNG reader.
       </Documentation>
     </StringVectorProperty>

     <Hints>
       <ReaderFactory extensions="abc"
                      file_description="Example File Format" />
    </Hints>
   </SourceProxy>
 </ProxyGroup>

</ServerManagerConfiguration> </source>

MyReaderGUI.xml

<source lang="xml"> <ParaViewReaders>

 <Reader name="MyReader" extensions="abc"

file_description="Example (.abc) Files">

 </Reader>

</ParaViewReaders> </source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.8)

FIND_PACKAGE(ParaView REQUIRED) INCLUDE(${PARAVIEW_USE_FILE})

ADD_PARAVIEW_PLUGIN(MyReader "1.0"
  SERVER_MANAGER_XML MyReader.xml
  SERVER_MANAGER_SOURCES MyReader.cxx
  GUI_RESOURCE_FILES MyReaderGUI.xml)

</source>