# ReadPolyData

VTKExamples/Cxx/IO/ReadPolyData

### Description

This example reads a polygonal data (.vtp) file. An example data set can be found at VTKData/Data/SyntheticPolyline.vtp

### Code

ReadPolyData.cxx

    #include <vtkXMLPolyDataReader.h>
    #include <vtkSmartPointer.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main ( int argc, char *argv[] )
    {
      // Parse command line arguments
      if(argc != 2)
      {
        std::cerr << "Usage: " << argv[0]
                  << " Filename(.vtp)" << std::endl;
        return EXIT_FAILURE;
      }

      std::string filename = argv[1];

      // Read all the data from the file
      vtkSmartPointer<vtkXMLPolyDataReader> reader =
        vtkSmartPointer<vtkXMLPolyDataReader>::New();
      reader->SetFileName(filename.c_str());
      reader->Update();

      // Visualize
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(reader->GetOutputPort());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderer->AddActor(actor);
      renderer->SetBackground(.3, .6, .3); // Background color green

      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ReadPolyData)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(ReadPolyData MACOSX_BUNDLE ReadPolyData.cxx )

    target_link_libraries(ReadPolyData ${VTK_LIBRARIES})

### Download and Build ReadPolyData

Click here to download ReadPolyData and its CMakeLists.txt file. Once the tarball ReadPolyData.tar has been downloaded and extracted,

    cd ReadPolyData/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./ReadPolyData

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.