TissueLens
VTKExamples/Cxx/Medical/TissueLens
Description¶
This example uses two clip filters to achieve a "tissue lens" affect. First, a sphere implicit function is used to clip a spherical hole in the extracted isosurface. Then a geometric sphere samples the original volume data using a probe filter. The resulting scalar point data is used to clip the sphere surface with the isosurface value.
Code¶
TissueLens.cxx
#include <vtkSmartPointer.h> #include <vtkMarchingCubes.h> #include <vtkMetaImageReader.h> #include <vtkSphereSource.h> #include <vtkProbeFilter.h> #include <vtkSphere.h> #include <vtkClipDataSet.h> #include <vtkImplicitVolume.h> #include <vtkUnstructuredGrid.h> #include <vtkLookupTable.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkDataSetMapper.h> #include <vtkPolyDataMapper.h> #include <vtkProperty.h> #include <vtkActor.h> #include <vtkCamera.h> #include <vtkProperty.h> int main (int argc, char *argv[]) { if (argc < 2) { cout << "Usage: " << argv[0] << " file.mhd" << endl; return EXIT_FAILURE; } // Read the volume data vtkSmartPointer<vtkMetaImageReader> reader = vtkSmartPointer<vtkMetaImageReader>::New(); reader->SetFileName (argv[1]); reader->Update(); // An isosurface, or contour value of 500 is known to correspond to the // skin of the patient. vtkSmartPointer<vtkMarchingCubes> skinExtractor = vtkSmartPointer<vtkMarchingCubes>::New(); skinExtractor->SetInputConnection(reader->GetOutputPort()); skinExtractor->SetValue(0, 500); // Define a spherical clip function to clip the isosurface vtkSmartPointer<vtkSphere> clipFunction = vtkSmartPointer<vtkSphere>::New(); clipFunction->SetRadius(50); clipFunction->SetCenter(73, 52, 15); // Clip the isosurface with a sphere vtkSmartPointer<vtkClipDataSet> skinClip = vtkSmartPointer<vtkClipDataSet>::New(); skinClip->SetInputConnection(skinExtractor->GetOutputPort()); skinClip->SetClipFunction(clipFunction); skinClip->SetValue(0); skinClip->GenerateClipScalarsOn(); skinClip->Update(); vtkSmartPointer<vtkDataSetMapper> skinMapper = vtkSmartPointer<vtkDataSetMapper>::New(); skinMapper->SetInputConnection(skinClip->GetOutputPort()); skinMapper->ScalarVisibilityOff(); vtkSmartPointer<vtkActor> skin = vtkSmartPointer<vtkActor>::New(); skin->SetMapper(skinMapper); skin->GetProperty()->SetDiffuseColor(1, .49, .25); vtkSmartPointer<vtkProperty> backProp = vtkSmartPointer<vtkProperty>::New(); backProp->SetDiffuseColor(0.8900, 0.8100, 0.3400); skin->SetBackfaceProperty(backProp); // Define a model for the "lens". Its geometry matches the implicit // sphere used to clip the isosurface vtkSmartPointer<vtkSphereSource> lensModel = vtkSmartPointer<vtkSphereSource>::New(); lensModel->SetRadius(50); lensModel->SetCenter(73, 52, 15); lensModel->SetPhiResolution(201); lensModel->SetThetaResolution(101); // Sample the input volume with the lens model geometry vtkSmartPointer<vtkProbeFilter> lensProbe = vtkSmartPointer<vtkProbeFilter>::New(); lensProbe->SetInputConnection(lensModel->GetOutputPort()); lensProbe->SetSourceConnection(reader->GetOutputPort()); // Clip the lens data with the isosurface value vtkSmartPointer<vtkClipDataSet> lensClip = vtkSmartPointer<vtkClipDataSet>::New(); lensClip->SetInputConnection(lensProbe->GetOutputPort()); lensClip->SetValue(500); lensClip->GenerateClipScalarsOff(); lensClip->Update(); // Define a suitable grayscale lut vtkSmartPointer<vtkLookupTable> bwLut = vtkSmartPointer<vtkLookupTable>::New(); bwLut->SetTableRange (0, 2048); bwLut->SetSaturationRange (0, 0); bwLut->SetHueRange (0, 0); bwLut->SetValueRange (.2, 1); bwLut->Build(); vtkSmartPointer<vtkDataSetMapper> lensMapper = vtkSmartPointer<vtkDataSetMapper>::New(); lensMapper->SetInputConnection(lensClip->GetOutputPort()); lensMapper->SetScalarRange(lensClip->GetOutput()->GetScalarRange()); lensMapper->SetLookupTable(bwLut); vtkSmartPointer<vtkActor> lens = vtkSmartPointer<vtkActor>::New(); lens->SetMapper(lensMapper); // 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. vtkSmartPointer<vtkCamera> aCamera = vtkSmartPointer<vtkCamera>::New(); 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); // 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. // vtkSmartPointer<vtkRenderer> aRenderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New(); renWin->AddRenderer(aRenderer); vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New(); iren->SetRenderWindow(renWin); // 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(lens); 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(.2, .3, .4); renWin->SetSize(640, 480); // 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. iren->Initialize(); iren->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(TissueLens) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(TissueLens MACOSX_BUNDLE TissueLens.cxx) target_link_libraries(TissueLens ${VTK_LIBRARIES})
Download and Build TissueLens¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download TissueLens and its CMakeLists.txt file. Once the tarball TissueLens.tar has been downloaded and extracted,
cd TissueLens/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:
./TissueLens
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.