# Point

VTKExamples/Cxx/GeometricObjects/Point

### Code

Point.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkPoints.h>
    #include <vtkCellArray.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main(int, char *[])
    {
      // Create the geometry of a point (the coordinate)
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      const float p[3] = {1.0, 2.0, 3.0};

      // Create the topology of the point (a vertex)
      vtkSmartPointer<vtkCellArray> vertices =
        vtkSmartPointer<vtkCellArray>::New();
      vtkIdType pid[1];
      pid[0] = points->InsertNextPoint(p);
      vertices->InsertNextCell(1,pid);

      // Create a polydata object
      vtkSmartPointer<vtkPolyData> point =
        vtkSmartPointer<vtkPolyData>::New();

      // Set the points and vertices we created as the geometry and topology of the polydata
      point->SetPoints(points);
      point->SetVerts(vertices);

      // Visualize
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
    #if VTK_MAJOR_VERSION <= 5
      mapper->SetInput(point);
    #else
      mapper->SetInputData(point);
    #endif

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->SetPointSize(20);

      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);

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Point)

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

    add_executable(Point MACOSX_BUNDLE Point.cxx )

    target_link_libraries(Point ${VTK_LIBRARIES})

### Download and Build Point

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

    cd Point/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:

    ./Point

WINDOWS USERS

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