EdgePoints
VTKExamples/Cxx/Visualization/EdgePoints
Description¶
This example uses vtkEdgePoints to generat a set of points that lie on an isosurface. Points are generated along the edges of cells that starddle the given iso value. Unlike vtkMarchingCubes it does not generate normals at the points.
Code¶
EdgePoints.cxx
#include <vtkSmartPointer.h> #include <vtkEdgePoints.h> #include <vtkActor.h> #include <vtkCamera.h> #include <vtkMetaImageReader.h> #include <vtkNamedColors.h> #include <vtkOutlineFilter.h> #include <vtkPolyDataMapper.h> #include <vtkProperty.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <array> #include <string> int main (int argc, char *argv[]) { if (argc < 2) { cout << "Usage: " << argv[0] << " file.mhd" << endl; return EXIT_FAILURE; } double isoValue = 0.0; if (argc > 2) { isoValue = std::stod(std::string(argv[2])); } vtkSmartPointer<vtkNamedColors> colors = vtkSmartPointer<vtkNamedColors>::New(); std::array<unsigned char , 4> isoColor{{255, 125, 64}}; colors->SetColor("IsoColor", isoColor.data()); std::array<unsigned char , 4> bkg{{51, 77, 102, 255}}; colors->SetColor("BkgColor", bkg.data()); vtkSmartPointer<vtkRenderer> aRenderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New(); renWin->AddRenderer(aRenderer); vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New(); iren->SetRenderWindow(renWin); vtkSmartPointer<vtkMetaImageReader> reader = vtkSmartPointer<vtkMetaImageReader>::New(); reader->SetFileName (argv[1]); vtkSmartPointer<vtkEdgePoints> isoExtractor = vtkSmartPointer<vtkEdgePoints>::New(); isoExtractor->SetInputConnection(reader->GetOutputPort()); isoExtractor->SetValue(isoValue); vtkSmartPointer<vtkPolyDataMapper> isoMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); isoMapper->SetInputConnection(isoExtractor->GetOutputPort()); isoMapper->ScalarVisibilityOff(); vtkSmartPointer<vtkActor> iso = vtkSmartPointer<vtkActor>::New(); iso->SetMapper(isoMapper); iso->GetProperty()->SetDiffuseColor(colors->GetColor3d("IsoColor").GetData()); // An outline provides context around the data. // vtkSmartPointer<vtkOutlineFilter> outlineData = vtkSmartPointer<vtkOutlineFilter>::New(); outlineData->SetInputConnection(reader->GetOutputPort()); vtkSmartPointer<vtkPolyDataMapper> mapOutline = vtkSmartPointer<vtkPolyDataMapper>::New(); mapOutline->SetInputConnection(outlineData->GetOutputPort()); vtkSmartPointer<vtkActor> outline = vtkSmartPointer<vtkActor>::New(); 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. 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); // 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(iso); 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); // 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(EdgePoints) find_package(VTK COMPONENTS vtkCommonColor vtkCommonCore vtkFiltersGeneral vtkFiltersModeling vtkIOImage vtkInteractionStyle vtkRenderingContextOpenGL2 vtkRenderingCore vtkRenderingFreeType vtkRenderingGL2PSOpenGL2 vtkRenderingOpenGL2 QUIET) if (NOT VTK_FOUND) message("Skipping EdgePoints: ${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(EdgePoints MACOSX_BUNDLE EdgePoints.cxx ) target_link_libraries(EdgePoints PRIVATE ${VTK_LIBRARIES}) else () # include all components add_executable(EdgePoints MACOSX_BUNDLE EdgePoints.cxx ) target_link_libraries(EdgePoints PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS EdgePoints MODULES ${VTK_LIBRARIES} ) endif ()
Download and Build EdgePoints¶
Click here to download EdgePoints and its CMakeLists.txt file. Once the tarball EdgePoints.tar has been downloaded and extracted,
cd EdgePoints/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:
./EdgePoints
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.