MarchingCubes

Description¶

Creates a surface from a volume using Flying Edges or Marching Cubes.

Without arguments, the examples generates a voxelized sphere with vtkVoxelModeller.

Note

vtkVoxelModeller by default produces a VTK_BIT scalar image. Marching Cubes does not support this type. The scalar output is set to float for this example.

To generate a surface from a DICOM series, provide a folder containing the series and specify an isovalue for the surface.

This Midas Repository contains a number of DICOM datasets.

Other languages

See (Python), (PythonicAPI), (CSharp)

Question

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

Code¶

MarchingCubes.cxx

#include <vtkActor.h>
#include <vtkDICOMImageReader.h>
#include <vtkImageData.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
#include <vtkVersion.h>
#include <vtkVoxelModeller.h>

// vtkFlyingEdges3D was introduced in VTK >= 8.2
#if VTK_MAJOR_VERSION >= 9 || (VTK_MAJOR_VERSION >= 8 && VTK_MINOR_VERSION >= 2)
#define USE_FLYING_EDGES
#else
#undef USE_FLYING_EDGES
#endif

#ifdef USE_FLYING_EDGES
#include <vtkFlyingEdges3D.h>
#else
#include <vtkMarchingCubes.h>
#endif

int main(int argc, char* argv[])
{
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkImageData> volume;
  double isoValue;
  if (argc < 3)
  {
    vtkNew<vtkSphereSource> sphereSource;
    sphereSource->SetPhiResolution(20);
    sphereSource->SetThetaResolution(20);
    sphereSource->Update();

    double bounds[6];
    sphereSource->GetOutput()->GetBounds(bounds);
    for (unsigned int i = 0; i < 6; i += 2)
    {
      double range = bounds[i + 1] - bounds[i];
      bounds[i] = bounds[i] - 0.1 * range;
      bounds[i + 1] = bounds[i + 1] + 0.1 * range;
    }
    vtkNew<vtkVoxelModeller> voxelModeller;
    voxelModeller->SetSampleDimensions(50, 50, 50);
    voxelModeller->SetModelBounds(bounds);
    voxelModeller->SetScalarTypeToFloat();
    voxelModeller->SetMaximumDistance(0.1);

    voxelModeller->SetInputConnection(sphereSource->GetOutputPort());
    voxelModeller->Update();
    isoValue = 0.5;
    volume->DeepCopy(voxelModeller->GetOutput());
  }
  else
  {
    vtkNew<vtkDICOMImageReader> reader;
    reader->SetDirectoryName(argv[1]);
    reader->Update();
    volume->DeepCopy(reader->GetOutput());
    isoValue = atof(argv[2]);
  }

#ifdef USE_FLYING_EDGES
  vtkNew<vtkFlyingEdges3D> surface;
#else
  vtkNew<vtkMarchingCubes> surface;
#endif
  surface->SetInputData(volume);
  surface->ComputeNormalsOn();
  surface->SetValue(0, isoValue);

  vtkNew<vtkRenderer> renderer;
  renderer->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("MarchingCubes");

  vtkNew<vtkRenderWindowInteractor> interactor;
  interactor->SetRenderWindow(renderWindow);

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(surface->GetOutputPort());
  mapper->ScalarVisibilityOff();

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());

  renderer->AddActor(actor);

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(MarchingCubes)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersCore
  FiltersSources
  IOImage
  ImagingHybrid
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "MarchingCubes: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(MarchingCubes MACOSX_BUNDLE MarchingCubes.cxx )
  target_link_libraries(MarchingCubes PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS MarchingCubes
  MODULES ${VTK_LIBRARIES}
)

Download and Build MarchingCubes¶

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

cd MarchingCubes/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:

./MarchingCubes

WINDOWS USERS

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