MarchingCubes

VTKExamples/Cxx/Modelling/MarchingCubes


Description

Creates a surface from a volume using Marching Cubes.

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.

Code

MarchingCubes.cxx

#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkMarchingCubes.h>
#include <vtkVoxelModeller.h>
#include <vtkSphereSource.h>
#include <vtkImageData.h>
#include <vtkDICOMImageReader.h>

#include <vtkActor.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>

int main(int argc, char *argv[])
{
  vtkSmartPointer<vtkImageData> volume =
    vtkSmartPointer<vtkImageData>::New();
  double isoValue;
  if (argc < 3)
  {
    vtkSmartPointer<vtkSphereSource> sphereSource =
      vtkSmartPointer<vtkSphereSource>::New();
    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] - .1 * range;
      bounds[i+1] = bounds[i+1] + .1 * range;
    }
    vtkSmartPointer<vtkVoxelModeller> voxelModeller =
      vtkSmartPointer<vtkVoxelModeller>::New();
    voxelModeller->SetSampleDimensions(50,50,50);
    voxelModeller->SetModelBounds(bounds);
    voxelModeller->SetScalarTypeToFloat();
    voxelModeller->SetMaximumDistance(.1);

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

  vtkSmartPointer<vtkMarchingCubes> surface =
    vtkSmartPointer<vtkMarchingCubes>::New();

#if VTK_MAJOR_VERSION <= 5
  surface->SetInput(volume);
#else
  surface->SetInputData(volume);
#endif
  surface->ComputeNormalsOn();
  surface->SetValue(0, isoValue);

  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderer->SetBackground(.1, .2, .3);

  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(surface->GetOutputPort());
  mapper->ScalarVisibilityOff();

  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);

  renderer->AddActor(actor);

  renderWindow->Render();
  interactor->Start();
  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(MarchingCubes)

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

add_executable(MarchingCubes MACOSX_BUNDLE MarchingCubes.cxx )

target_link_libraries(MarchingCubes ${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.