# BlankPoint

VTKExamples/Cxx/StructuredGrid/BlankPoint

### Code

BlankPoint.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkIdList.h>
    #include <vtkProperty.h>
    #include <vtkStructuredGrid.h>
    #include <vtkXMLStructuredGridWriter.h>
    #include <vtkMath.h>
    #include <vtkDataSetMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkStructuredGridGeometryFilter.h>
    #include <vtkXMLPolyDataWriter.h>
    #include <vtkXMLStructuredGridWriter.h>

    int main(int, char *[])
    {
      // Create a grid
      vtkSmartPointer<vtkStructuredGrid> structuredGrid =
        vtkSmartPointer<vtkStructuredGrid>::New();

      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();

      unsigned int gridSize = 8;
      unsigned int counter = 0;
      // Create a 5x5 grid of points
      for(unsigned int j = 0; j < gridSize; j++)
      {
        for(unsigned int i = 0; i < gridSize; i++)
        {
          if(i == 3 && j == 3) // Make one point higher than the rest
          {
            points->InsertNextPoint(i, j, 2);
        std::cout << "The different point is number " << counter << std::endl;
          }
          else
          {
            points->InsertNextPoint(i, j, 0); // Make most of the points the same height
          }
          counter++;
        }
      }

      // Specify the dimensions of the grid
      structuredGrid->SetDimensions(gridSize,gridSize,1);

      structuredGrid->SetPoints(points);

      structuredGrid->BlankPoint(27);
      structuredGrid->Modified();

      // Create a mapper and actor
      vtkSmartPointer<vtkDataSetMapper> gridMapper =
        vtkSmartPointer<vtkDataSetMapper>::New();
    #if VTK_MAJOR_VERSION <= 5
      gridMapper->SetInputConnection(structuredGrid->GetProducerPort());
    #else
      gridMapper->SetInputData(structuredGrid);
    #endif

      vtkSmartPointer<vtkActor> gridActor =
        vtkSmartPointer<vtkActor>::New();
      gridActor->SetMapper(gridMapper);
      gridActor->GetProperty()->EdgeVisibilityOn();
      gridActor->GetProperty()->SetEdgeColor(0,0,1);

      // Create a renderer, render window, and interactor
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      // Add the actor to the scene
      renderer->AddActor(gridActor);
      renderer->SetBackground(.3, .6, .3); // Background color green

      // Render and interact
      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(BlankPoint)

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

    add_executable(BlankPoint MACOSX_BUNDLE BlankPoint.cxx)

    target_link_libraries(BlankPoint ${VTK_LIBRARIES})

### Download and Build BlankPoint

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

    cd BlankPoint/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:

    ./BlankPoint

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.