AreaPicking
VTKExamples/Cxx/Picking/AreaPicking
Description¶
This example creates 3 points+vertices. Currently, the address of the picked prop is 0 (this is not correct). A red bounding box is drawn around every picked prop.
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For '' vtkInteractorStyleTrackballCamera''' - use 'p' to pick at the current mouse position
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For '' vtkInteractorStyleRubberBandPick''' - use 'r' and left-mouse to draw a selection box used to pick
Question
If you have a simple question about this example contact us at VTKExamplesProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum
Code¶
AreaPicking.cxx
#include <vtkActor.h> #include <vtkAreaPicker.h> #include <vtkCallbackCommand.h> #include <vtkCellArray.h> #include <vtkInteractorStyleRubberBandPick.h> #include <vtkInteractorStyleTrackball.h> #include <vtkInteractorStyleTrackballCamera.h> #include <vtkNamedColors.h> #include <vtkPoints.h> #include <vtkPolyData.h> #include <vtkPolyDataMapper.h> #include <vtkProp3DCollection.h> #include <vtkProperty.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include <vtkSmartPointer.h> #include <vtkXMLPolyDataWriter.h> namespace { void PickCallbackFunction(vtkObject* caller, long unsigned int eventId, void* clientData, void* callData); } int main(int, char*[]) { // Create a set of points vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); vtkSmartPointer<vtkCellArray> vertices = vtkSmartPointer<vtkCellArray>::New(); vtkIdType pid[1]; pid[0] = points->InsertNextPoint(1.0, 0.0, 0.0); vertices->InsertNextCell(1, pid); pid[0] = points->InsertNextPoint(0.0, 0.0, 0.0); vertices->InsertNextCell(1, pid); pid[0] = points->InsertNextPoint(0.0, 1.0, 0.0); vertices->InsertNextCell(1, pid); // Create a polydata vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New(); polydata->SetPoints(points); polydata->SetVerts(vertices); // Visualize vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New(); mapper->SetInputData(polydata); vtkSmartPointer<vtkNamedColors> colors = vtkSmartPointer<vtkNamedColors>::New(); vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New(); actor->SetMapper(mapper); actor->GetProperty()->SetPointSize(5); actor->GetProperty()->SetColor(colors->GetColor3d("Black").GetData()); vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); vtkSmartPointer<vtkAreaPicker> areaPicker = vtkSmartPointer<vtkAreaPicker>::New(); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); renderWindowInteractor->SetRenderWindow(renderWindow); renderWindowInteractor->SetPicker(areaPicker); renderer->AddActor(actor); renderer->SetBackground(colors->GetColor3d("Gold").GetData()); renderWindow->Render(); // For vtkInteractorStyleRubberBandPick - use 'r' and left-mouse to draw a // selection box used to pick vtkSmartPointer<vtkInteractorStyleRubberBandPick> style = vtkSmartPointer<vtkInteractorStyleRubberBandPick>::New(); // For vtkInteractorStyleTrackballCamera - use 'p' to pick at the current // mouse position // vtkSmartPointer<vtkInteractorStyleTrackballCamera> style = // vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New(); //like // paraview style->SetCurrentRenderer(renderer); renderWindowInteractor->SetInteractorStyle(style); vtkSmartPointer<vtkCallbackCommand> pickCallback = vtkSmartPointer<vtkCallbackCommand>::New(); pickCallback->SetCallback(PickCallbackFunction); areaPicker->AddObserver(vtkCommand::EndPickEvent, pickCallback); renderWindowInteractor->Start(); return EXIT_SUCCESS; } namespace { void PickCallbackFunction(vtkObject* caller, long unsigned int vtkNotUsed(eventId), void* vtkNotUsed(clientData), void* vtkNotUsed(callData)) { std::cout << "Pick." << std::endl; vtkAreaPicker* areaPicker = static_cast<vtkAreaPicker*>(caller); vtkProp3DCollection* props = areaPicker->GetProp3Ds(); props->InitTraversal(); for (vtkIdType i = 0; i < props->GetNumberOfItems(); i++) { vtkProp3D* prop = props->GetNextProp3D(); std::cout << "Picked prop: " << prop << std::endl; } } } // namespace
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR) project(AreaPicking) find_package(VTK COMPONENTS vtkCommonColor vtkCommonCore vtkCommonDataModel vtkIOXML vtkInteractionStyle vtkRenderingContextOpenGL2 vtkRenderingCore vtkRenderingFreeType vtkRenderingGL2PSOpenGL2 vtkRenderingOpenGL2 QUIET) if (NOT VTK_FOUND) message("Skipping AreaPicking: ${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(AreaPicking MACOSX_BUNDLE AreaPicking.cxx ) target_link_libraries(AreaPicking PRIVATE ${VTK_LIBRARIES}) else () # include all components add_executable(AreaPicking MACOSX_BUNDLE AreaPicking.cxx ) target_link_libraries(AreaPicking PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS AreaPicking MODULES ${VTK_LIBRARIES} ) endif ()
Download and Build AreaPicking¶
Click here to download AreaPicking and its CMakeLists.txt file. Once the tarball AreaPicking.tar has been downloaded and extracted,
cd AreaPicking/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:
./AreaPicking
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.