# ParticleReader

VTKExamples/Cxx/IO/ParticleReader

### Description

This example reads ascii files where each line consists of points with its position (x,y,z) and (optionally) one scalar or binary files in RAW 3d file format.

Other Languages

See (CSharp)

### Code

ParticleReader.cxx

    //
    // This example reads ascii files where each line consists of points with its position (x,y,z)
    // and (optionally) one scalar or binary files in RAW 3d file format.
    //
    // some standard vtk headers
    #include <vtkSmartPointer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>

    // headers needed for this example
    #include <vtkParticleReader.h>
    #include <vtkPolyDataMapper.h>

    // needed to easily convert int to std::string
    int main(int argc, char* argv[])
    {
       // Verify input arguments
       if ( argc != 2 )
       {
          std::cout << "Usage: " << argv[0]
          << " Filename(.raw)" << std::endl;
          return EXIT_FAILURE;
       }

       std::string filePath = argv[1];
       // Particles.raw supplied by VTK is big endian encoded
       //std::string filePath = "C:\\VTK\\vtkdata-5.8.0\\Data\\Particles.raw";
       // Read the file
       vtkSmartPointer<vtkParticleReader> reader =
          vtkSmartPointer<vtkParticleReader>::New();

       reader->SetFileName ( filePath.c_str() );
       // if nothing gets displayed or totally wrong, swap the endianness
       reader->SetDataByteOrderToBigEndian();
       reader->Update();

       // Visualize
       vtkSmartPointer<vtkPolyDataMapper> mapper =
          vtkSmartPointer<vtkPolyDataMapper>::New();
       mapper->SetInputConnection(reader->GetOutputPort());
       std::cout << "number of pieces: " << mapper->GetNumberOfPieces() << std::endl;
       mapper->SetScalarRange(4, 9);

       vtkSmartPointer<vtkActor> actor =
          vtkSmartPointer<vtkActor>::New();

       actor->SetMapper(mapper);
       actor->GetProperty()->SetPointSize(4);

       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(.2, .3, .4);

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

       return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(ParticleReader)

    find_package(VTK COMPONENTS
      vtkCommonCore
      vtkIOGeometry
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping ParticleReader: ${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(ParticleReader MACOSX_BUNDLE ParticleReader.cxx )
      target_link_libraries(ParticleReader PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(ParticleReader MACOSX_BUNDLE ParticleReader.cxx )
      target_link_libraries(ParticleReader PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS ParticleReader
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build ParticleReader

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

    cd ParticleReader/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:

    ./ParticleReader

WINDOWS USERS

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