ExtractSelection
VTKExamples/Cxx/PolyData/ExtractSelection
Description¶
This example creates 50 random points and extracts 10 of them (the points with ids 10-19).
Code¶
ExtractSelection.cxx
#include <vtkVersion.h> #include <vtkSmartPointer.h> #include <vtkInformation.h> #include <vtkPointSource.h> #include <vtkExtractSelection.h> #include <vtkSelection.h> #include <vtkSelectionNode.h> #include <vtkPolyData.h> #include <vtkUnstructuredGrid.h> #include <vtkIdTypeArray.h> #include <vtkDataSetMapper.h> #include <vtkProperty.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include <vtkSphereSource.h> #include <vtkVertexGlyphFilter.h> int main(int, char *[]) { vtkSmartPointer<vtkPointSource> pointSource = vtkSmartPointer<vtkPointSource>::New(); pointSource->SetNumberOfPoints(50); pointSource->Update(); std::cout << "There are " << pointSource->GetOutput()->GetNumberOfPoints() << " input points." << std::endl; vtkSmartPointer<vtkIdTypeArray> ids = vtkSmartPointer<vtkIdTypeArray>::New(); ids->SetNumberOfComponents(1); // Set values for(unsigned int i = 10; i < 20; i++) { ids->InsertNextValue(i); } vtkSmartPointer<vtkSelectionNode> selectionNode = vtkSmartPointer<vtkSelectionNode>::New(); selectionNode->SetFieldType(vtkSelectionNode::POINT); selectionNode->SetContentType(vtkSelectionNode::INDICES); selectionNode->SetSelectionList(ids); vtkSmartPointer<vtkSelection> selection = vtkSmartPointer<vtkSelection>::New(); selection->AddNode(selectionNode); vtkSmartPointer<vtkExtractSelection> extractSelection = vtkSmartPointer<vtkExtractSelection>::New(); extractSelection->SetInputConnection(0, pointSource->GetOutputPort()); #if VTK_MAJOR_VERSION <= 5 extractSelection->SetInput(1, selection); #else extractSelection->SetInputData(1, selection); #endif extractSelection->Update(); // In selection vtkSmartPointer<vtkUnstructuredGrid> selected = vtkSmartPointer<vtkUnstructuredGrid>::New(); selected->ShallowCopy(extractSelection->GetOutput()); std::cout << "There are " << selected->GetNumberOfPoints() << " points in the selection." << std::endl; std::cout << "There are " << selected->GetNumberOfCells() << " cells in the selection." << std::endl; // Get points that are NOT in the selection selectionNode->GetProperties()->Set(vtkSelectionNode::INVERSE(), 1); //invert the selection extractSelection->Update(); vtkSmartPointer<vtkUnstructuredGrid> notSelected = vtkSmartPointer<vtkUnstructuredGrid>::New(); notSelected->ShallowCopy(extractSelection->GetOutput()); std::cout << "There are " << notSelected->GetNumberOfPoints() << " points NOT in the selection." << std::endl; std::cout << "There are " << notSelected->GetNumberOfCells() << " cells NOT in the selection." << std::endl; vtkSmartPointer<vtkDataSetMapper> inputMapper = vtkSmartPointer<vtkDataSetMapper>::New(); inputMapper->SetInputConnection(pointSource->GetOutputPort()); vtkSmartPointer<vtkActor> inputActor = vtkSmartPointer<vtkActor>::New(); inputActor->SetMapper(inputMapper); vtkSmartPointer<vtkDataSetMapper> selectedMapper = vtkSmartPointer<vtkDataSetMapper>::New(); #if VTK_MAJOR_VERSION <= 5 selectedMapper->SetInputConnection(selected->GetProducerPort()); #else selectedMapper->SetInputData(selected); #endif vtkSmartPointer<vtkActor> selectedActor = vtkSmartPointer<vtkActor>::New(); selectedActor->SetMapper(selectedMapper); vtkSmartPointer<vtkDataSetMapper> notSelectedMapper = vtkSmartPointer<vtkDataSetMapper>::New(); #if VTK_MAJOR_VERSION <= 5 notSelectedMapper->SetInputConnection(notSelected->GetProducerPort()); #else notSelectedMapper->SetInputData(notSelected); #endif vtkSmartPointer<vtkActor> notSelectedActor = vtkSmartPointer<vtkActor>::New(); notSelectedActor->SetMapper(notSelectedMapper); // There will be one render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->SetSize(900, 300); // And one interactor vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); interactor->SetRenderWindow(renderWindow); // Define viewport ranges // (xmin, ymin, xmax, ymax) double leftViewport[4] = {0.0, 0.0, 0.33, 1.0}; double centerViewport[4] = {0.33, 0.0, .66, 1.0}; double rightViewport[4] = {0.66, 0.0, 1.0, 1.0}; // Setup the renderers vtkSmartPointer<vtkRenderer> leftRenderer = vtkSmartPointer<vtkRenderer>::New(); renderWindow->AddRenderer(leftRenderer); leftRenderer->SetViewport(leftViewport); leftRenderer->SetBackground(.6, .5, .4); vtkSmartPointer<vtkRenderer> centerRenderer = vtkSmartPointer<vtkRenderer>::New(); renderWindow->AddRenderer(centerRenderer); centerRenderer->SetViewport(centerViewport); centerRenderer->SetBackground(.3, .1, .4); vtkSmartPointer<vtkRenderer> rightRenderer = vtkSmartPointer<vtkRenderer>::New(); renderWindow->AddRenderer(rightRenderer); rightRenderer->SetViewport(rightViewport); rightRenderer->SetBackground(.4, .5, .6); leftRenderer->AddActor(inputActor); centerRenderer->AddActor(selectedActor); rightRenderer->AddActor(notSelectedActor); leftRenderer->ResetCamera(); centerRenderer->ResetCamera(); rightRenderer->ResetCamera(); renderWindow->Render(); interactor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ExtractSelection) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ExtractSelection MACOSX_BUNDLE ExtractSelection.cxx) target_link_libraries(ExtractSelection ${VTK_LIBRARIES})
Download and Build ExtractSelection¶
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 ExtractSelection and its CMakeLists.txt file. Once the tarball ExtractSelection.tar has been downloaded and extracted,
cd ExtractSelection/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:
./ExtractSelection
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.