# HeadBone

VTKExamples/Cxx/VisualizationAlgorithms/HeadBone

### Description

This example generates an isosurface of human bone.

Info

See Figure 6-11b in Chapter 6 the VTK Textbook.

Other Languages

See (Python)

### Code

HeadBone.cxx

    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkMarchingCubes.h>
    #include <vtkMergePoints.h>
    #include <vtkMetaImageReader.h>
    #include <vtkNamedColors.h>
    #include <vtkOutlineFilter.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>

    int main (int argc, char *argv[])
    {
      if (argc < 2)
      {
        std::cout << "Usage: " << argv[0] << " FullHead.mhd" << std::endl;
        return EXIT_FAILURE;
      }

    // Create the RenderWindow, Renderer and both Actors
    //
      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      vtkSmartPointer<vtkRenderer> ren1 =
        vtkSmartPointer<vtkRenderer>::New();

      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);

      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

    // create pipeline
    //

      vtkSmartPointer<vtkMetaImageReader> reader =
        vtkSmartPointer<vtkMetaImageReader>::New();
      reader->SetFileName(argv[1]);
      reader->Update();

      vtkSmartPointer<vtkMergePoints> locator =
        vtkSmartPointer<vtkMergePoints>::New();
      locator->SetDivisions(64, 64, 92);
      locator->SetNumberOfPointsPerBucket(2);
      locator->AutomaticOff();

      vtkSmartPointer<vtkMarchingCubes> iso =
        vtkSmartPointer<vtkMarchingCubes>::New();
      iso->SetInputConnection(reader->GetOutputPort());
      iso->ComputeGradientsOn();
      iso->ComputeScalarsOff();
      iso->SetValue(0, 1150);
      iso->SetLocator(locator);

      vtkSmartPointer<vtkPolyDataMapper> isoMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      isoMapper->SetInputConnection(iso->GetOutputPort());
      isoMapper->ScalarVisibilityOff();

      vtkSmartPointer<vtkActor> isoActor =
        vtkSmartPointer<vtkActor>::New();
      isoActor->SetMapper(isoMapper);
      isoActor->GetProperty()->SetColor(colors->GetColor3d("Wheat").GetData());

      vtkSmartPointer<vtkOutlineFilter> outline =
        vtkSmartPointer<vtkOutlineFilter>::New();
      outline->SetInputConnection(reader->GetOutputPort());

      vtkSmartPointer<vtkPolyDataMapper> outlineMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      outlineMapper->SetInputConnection(outline->GetOutputPort());

      vtkSmartPointer<vtkActor> outlineActor =
        vtkSmartPointer<vtkActor>::New();
      outlineActor->SetMapper(outlineMapper);

    // Add the actors to the renderer, set the background and size
    //
      ren1->AddActor(outlineActor);
      ren1->AddActor(isoActor);
      ren1->SetBackground(colors->GetColor3d("SlateGray").GetData());
      ren1->GetActiveCamera()->SetFocalPoint(0, 0, 0);
      ren1->GetActiveCamera()->SetPosition(0, -1, 0);
      ren1->GetActiveCamera()->SetViewUp(0, 0, -1);
      ren1->ResetCamera();
      ren1->GetActiveCamera()->Dolly(1.5);
      ren1->ResetCameraClippingRange();

      renWin->SetSize(640, 480);

      renWin->Render();
      iren->Start();
      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(HeadBone)

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

### Download and Build HeadBone

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

    cd HeadBone/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:

    ./HeadBone

WINDOWS USERS

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