# Vol

VTKExamples/Cxx/StructuredPoints/Vol

### Code

Vol.cxx

    #include <vtkSmartPointer.h>
    #include <vtkStructuredPoints.h>

    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkDoubleArray.h>
    #include <vtkPointData.h>
    #include <vtkContourFilter.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkProperty.h>
    #include <vtkNamedColors.h>

    int main( int, char *[] )
    {
      int i, j, k, kOffset, jOffset, offset;
      double x, y, z, s, sp;

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

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      vtkSmartPointer<vtkStructuredPoints> vol =
        vtkSmartPointer<vtkStructuredPoints>::New();
      vol->SetDimensions(26,26,26);
      vol->SetOrigin(-0.5,-0.5,-0.5);
      sp = 1.0/25.0;
      vol->SetSpacing(sp, sp, sp);

      vtkSmartPointer<vtkDoubleArray> scalars =
        vtkSmartPointer<vtkDoubleArray>::New();
      scalars->SetNumberOfComponents(1);
      scalars->SetNumberOfTuples(26*26*26);
      for (k=0; k<26; k++)
      {
        z = -0.5 + k*sp;
        kOffset = k * 26 * 26;
        for (j=0; j<26; j++)
        {
          y = -0.5 + j*sp;
          jOffset = j * 26;
          for (i=0; i<26; i++)
          {
            x = -0.5 + i*sp;
            s = x*x + y*y + z*z - (0.4*0.4);
            offset = i + jOffset + kOffset;
            scalars->InsertTuple(offset,&s);
          }
        }
      }
      vol->GetPointData()->SetScalars(scalars);

      vtkSmartPointer<vtkContourFilter> contour =
        vtkSmartPointer<vtkContourFilter>::New();
      contour->SetInputData(vol);
      contour->SetValue(0,0.0);

      vtkSmartPointer<vtkPolyDataMapper> volMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      volMapper->SetInputConnection(contour->GetOutputPort());
      volMapper->ScalarVisibilityOff();
      vtkSmartPointer<vtkActor> volActor =
        vtkSmartPointer<vtkActor>::New();
      volActor->SetMapper(volMapper);
      volActor->GetProperty()->EdgeVisibilityOn();
      volActor->GetProperty()->SetColor(colors->GetColor3d("Salmon").GetData());
      renderer->AddActor(volActor);
      renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());
      renWin->SetSize(512,512);

      // interact with data
      renWin->Render();

      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Vol)

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

    add_executable(Vol MACOSX_BUNDLE Vol.cxx )

    target_link_libraries(Vol ${VTK_LIBRARIES})

### Download and Build Vol

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

    cd Vol/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:

    ./Vol

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.