Skip to content

MedicalDemo1

vtk-examples/Cxx/Medical/MedicalDemo1


Description

The skin extracted from a CT dataset of the head.

usage

MedicalDemo1 FullHead.mhd

Note

This original source code for this example is here.

Info

The example uses src/Testing/Data/FullHead.mhd which references src/Testing/Data/FullHead.raw.gz.

Other languages

See (Python), (Java)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

MedicalDemo1.cxx

// Derived from VTK/Examples/Cxx/Medical1.cxx
// This example reads a volume dataset, extracts an isosurface that
// represents the skin and displays it.
//

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

#include <array>

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

  vtkNew<vtkNamedColors> colors;

  std::array<unsigned char, 4> skinColor{{255, 125, 64}};
  colors->SetColor("SkinColor", skinColor.data());
  std::array<unsigned char, 4> bkg{{51, 77, 102, 255}};
  colors->SetColor("BkgColor", bkg.data());

  // Create the renderer, the render window, and the interactor. The renderer
  // draws into the render window, the interactor enables mouse- and
  // keyboard-based interaction with the data within the render window.
  //
  vtkNew<vtkRenderer> aRenderer;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(aRenderer);

  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  vtkNew<vtkMetaImageReader> reader;
  reader->SetFileName(argv[1]);

  // An isosurface, or contour value of 500 is known to correspond to the
  // skin of the patient.
  vtkNew<vtkMarchingCubes> skinExtractor;
  skinExtractor->SetInputConnection(reader->GetOutputPort());
  skinExtractor->SetValue(0, 500);

  vtkNew<vtkPolyDataMapper> skinMapper;
  skinMapper->SetInputConnection(skinExtractor->GetOutputPort());
  skinMapper->ScalarVisibilityOff();

  vtkNew<vtkActor> skin;
  skin->SetMapper(skinMapper);
  skin->GetProperty()->SetDiffuseColor(
      colors->GetColor3d("SkinColor").GetData());

  // An outline provides context around the data.
  //
  vtkNew<vtkOutlineFilter> outlineData;
  outlineData->SetInputConnection(reader->GetOutputPort());

  vtkNew<vtkPolyDataMapper> mapOutline;
  mapOutline->SetInputConnection(outlineData->GetOutputPort());

  vtkNew<vtkActor> outline;
  outline->SetMapper(mapOutline);
  outline->GetProperty()->SetColor(colors->GetColor3d("Black").GetData());

  // It is convenient to create an initial view of the data. The FocalPoint
  // and Position form a vector direction. Later on (ResetCamera() method)
  // this vector is used to position the camera to look at the data in
  // this direction.
  vtkNew<vtkCamera> aCamera;
  aCamera->SetViewUp(0, 0, -1);
  aCamera->SetPosition(0, -1, 0);
  aCamera->SetFocalPoint(0, 0, 0);
  aCamera->ComputeViewPlaneNormal();
  aCamera->Azimuth(30.0);
  aCamera->Elevation(30.0);

  // Actors are added to the renderer. An initial camera view is created.
  // The Dolly() method moves the camera towards the FocalPoint,
  // thereby enlarging the image.
  aRenderer->AddActor(outline);
  aRenderer->AddActor(skin);
  aRenderer->SetActiveCamera(aCamera);
  aRenderer->ResetCamera();
  aCamera->Dolly(1.5);

  // Set a background color for the renderer and set the size of the
  // render window (expressed in pixels).
  aRenderer->SetBackground(colors->GetColor3d("BkgColor").GetData());
  renWin->SetSize(640, 480);
  renWin->SetWindowName("MedicalDemo1");

  // Note that when camera movement occurs (as it does in the Dolly()
  // method), the clipping planes often need adjusting. Clipping planes
  // consist of two planes: near and far along the view direction. The
  // near plane clips out objects in front of the plane; the far plane
  // clips out objects behind the plane. This way only what is drawn
  // between the planes is actually rendered.
  aRenderer->ResetCameraClippingRange();

  // Initialize the event loop and then start it.
  renWin->Render();
  iren->Initialize();
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(MedicalDemo1)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkFiltersCore
  vtkFiltersModeling
  vtkIOImage
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping MedicalDemo1: ${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(MedicalDemo1 MACOSX_BUNDLE MedicalDemo1.cxx )
  target_link_libraries(MedicalDemo1 PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(MedicalDemo1 MACOSX_BUNDLE MedicalDemo1.cxx )
  target_link_libraries(MedicalDemo1 PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS MedicalDemo1
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build MedicalDemo1

Click here to download MedicalDemo1 and its CMakeLists.txt file. Once the tarball MedicalDemo1.tar has been downloaded and extracted,

cd MedicalDemo1/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:

./MedicalDemo1

WINDOWS USERS

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