# ReadPolyData

VTKExamples/Cxx/IO/ReadPolyData

### Description

This example reads a polygonal data (.vtp) file. An example data set can be found at Torso.vtp.

Other Languages

See (Python), (Java), (CSharp)

### Code

ReadPolyData.cxx

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

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

      std::string filename = argv[1];

      vtkSmartPointer<vtkNamedColors> colors =
          vtkSmartPointer<vtkNamedColors>::New();

      // 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);
      actor->GetProperty()->SetColor(colors->GetColor3d("BurlyWood").GetData());

      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(colors->GetColor3d("Teal").GetData());
      renderer->GetActiveCamera()->Pitch(90);
      renderer->GetActiveCamera()->SetViewUp(0, 0, 1);
      renderer->ResetCamera();

      renderWindow->SetSize(600, 600);
      renderWindow->Render();
      renderWindow->SetWindowName("ReadPolyData");
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(ReadPolyData)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkIOXML
      vtkInteractionStyle
      vtkRenderingContextOpenGL2
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingGL2PSOpenGL2
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping ReadPolyData: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(ReadPolyData MACOSX_BUNDLE ReadPolyData.cxx )
      target_link_libraries(ReadPolyData PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(ReadPolyData MACOSX_BUNDLE ReadPolyData.cxx )
      target_link_libraries(ReadPolyData PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS ReadPolyData
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### 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.