# Visualize2DPoints

VTKExamples/Cxx/Visualization/Visualize2DPoints

### Description

This example shows how to render a set of points. The example reads the points from a vtp file specified as the first command line argument. An example data set can be found here.

### Code

Visualize2DPoints.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyDataMapper2D.h>
    #include <vtkActor2D.h>
    #include <vtkMath.h>
    #include <vtkProperty2D.h>
    #include <vtkCellArray.h>
    #include <vtkPolyData.h>
    #include <vtkXMLPolyDataReader.h>

    int main(int argc, char* argv[])
    {
      if(argc != 2)
      {
        std::cout << "Required parameters: Filename" << std::endl;
        return EXIT_FAILURE;
      }

      std::string inputFilename = argv[1];

      vtkSmartPointer<vtkXMLPolyDataReader> reader =
        vtkSmartPointer<vtkXMLPolyDataReader>::New();
      reader->SetFileName(inputFilename.c_str());
      reader->Update();
      vtkPolyData* polydata = reader->GetOutput();
      //vtkPoints* Points = Polydata->GetPoints();

      vtkSmartPointer<vtkActor2D> actor =
        vtkSmartPointer<vtkActor2D>::New();
      double color[3] = {1,1,1};

      vtkSmartPointer<vtkPolyDataMapper2D> mapper =
        vtkSmartPointer<vtkPolyDataMapper2D>::New();
    #if VTK_MAJOR_VERSION <= 5
      mapper->SetInput( polydata );
    #else
      mapper->SetInputData( polydata );
    #endif
      mapper->ScalarVisibilityOff();
      actor->SetMapper( mapper );

      vtkProperty2D *property2D = actor->GetProperty();
      property2D->SetColor( color );
      property2D->SetPointSize( 2.0 );

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderer->AddActor(actor);

      // Renderer and RenderWindow
      renderer->SetBackground( 0, 0, 0);
      renderer->ResetCamera();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();

      renderWindow->SetSize( 200,200 );
      renderWindow->AddRenderer( renderer );
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow( renderWindow );

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Visualize2DPoints)

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

    add_executable(Visualize2DPoints MACOSX_BUNDLE Visualize2DPoints.cxx )

    target_link_libraries(Visualize2DPoints ${VTK_LIBRARIES})

### Download and Build Visualize2DPoints

Click here to download Visualize2DPoints and its CMakeLists.txt file. Once the tarball Visualize2DPoints.tar has been downloaded and extracted,

    cd Visualize2DPoints/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:

    ./Visualize2DPoints

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