CellEdgeNeighbors
VTKExamples/Cxx/PolyData/CellEdgeNeighbors
Description¶
Determine which cells share an edge with a specified cell.
Code¶
CellEdgeNeighbors.cxx
#include <vtkVersion.h> #include <vtkSmartPointer.h> #include <vtkSphereSource.h> #include <vtkPolyData.h> #include <vtkIdList.h> #include <vtkCell.h> #include <vtkTriangleFilter.h> #include <vtkDataSetMapper.h> #include <vtkActor.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> #include <vtkIdTypeArray.h> #include <vtkSelectionNode.h> #include <vtkSelection.h> #include <vtkExtractSelection.h> #include <vtkProperty.h> #include <list> int main(int, char *[]) { // Create a sphere vtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New(); sphereSource->Update(); vtkSmartPointer<vtkTriangleFilter> triangleFilter = vtkSmartPointer<vtkTriangleFilter>::New(); triangleFilter->SetInputConnection(sphereSource->GetOutputPort()); triangleFilter->Update(); vtkIdType cellId = 0; vtkSmartPointer<vtkIdList> cellPointIds = vtkSmartPointer<vtkIdList>::New(); triangleFilter->GetOutput()->GetCellPoints(cellId, cellPointIds); std::list<vtkIdType> neighbors; for(vtkIdType i = 0; i < cellPointIds->GetNumberOfIds(); i++) { vtkSmartPointer<vtkIdList> idList = vtkSmartPointer<vtkIdList>::New(); //add one of the edge points idList->InsertNextId(cellPointIds->GetId(i)); //add the other edge point if(i+1 == cellPointIds->GetNumberOfIds()) { idList->InsertNextId(cellPointIds->GetId(0)); } else { idList->InsertNextId(cellPointIds->GetId(i+1)); } //get the neighbors of the cell vtkSmartPointer<vtkIdList> neighborCellIds = vtkSmartPointer<vtkIdList>::New(); triangleFilter->GetOutput()->GetCellNeighbors(cellId, idList, neighborCellIds); for(vtkIdType j = 0; j < neighborCellIds->GetNumberOfIds(); j++) { neighbors.push_back(neighborCellIds->GetId(j)); } } std::cout << "Edge neighbor ids are: " << std::endl; for(std::list<vtkIdType>::iterator it1 = neighbors.begin(); it1 != neighbors.end(); it1++) { std::cout << " " << *it1; } std::cout << std::endl; vtkSmartPointer<vtkDataSetMapper> sphereMapper = vtkSmartPointer<vtkDataSetMapper>::New(); sphereMapper->SetInputConnection(sphereSource->GetOutputPort()); vtkSmartPointer<vtkActor> sphereActor = vtkSmartPointer<vtkActor>::New(); sphereActor->SetMapper(sphereMapper); sphereActor->GetProperty()->SetEdgeColor(0, 0, 0); sphereActor->GetProperty()->EdgeVisibilityOn(); vtkSmartPointer<vtkDataSetMapper> mainCellMapper = vtkSmartPointer<vtkDataSetMapper>::New(); vtkSmartPointer<vtkDataSetMapper> neighborCellsMapper = vtkSmartPointer<vtkDataSetMapper>::New(); // Create a dataset with the cell of interest { vtkSmartPointer<vtkIdTypeArray> ids = vtkSmartPointer<vtkIdTypeArray>::New(); ids->SetNumberOfComponents(1); ids->InsertNextValue(cellId); vtkSmartPointer<vtkSelectionNode> selectionNode = vtkSmartPointer<vtkSelectionNode>::New(); selectionNode->SetFieldType(vtkSelectionNode::CELL); 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, sphereSource->GetOutputPort()); #if VTK_MAJOR_VERSION <= 5 extractSelection->SetInput(1, selection); #else extractSelection->SetInputData(1, selection); #endif extractSelection->Update(); mainCellMapper->SetInputConnection(extractSelection->GetOutputPort()); } vtkSmartPointer<vtkActor> mainCellActor = vtkSmartPointer<vtkActor>::New(); mainCellActor->SetMapper(mainCellMapper); mainCellActor->GetProperty()->SetColor(1,0,0); // Create a dataset with the neighbor cells { vtkSmartPointer<vtkIdTypeArray> ids = vtkSmartPointer<vtkIdTypeArray>::New(); ids->SetNumberOfComponents(1); for(std::list<vtkIdType>::iterator it1 = neighbors.begin(); it1 != neighbors.end(); it1++) { ids->InsertNextValue(*it1); } vtkSmartPointer<vtkSelectionNode> selectionNode = vtkSmartPointer<vtkSelectionNode>::New(); selectionNode->SetFieldType(vtkSelectionNode::CELL); 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, sphereSource->GetOutputPort()); #if VTK_MAJOR_VERSION <= 5 extractSelection->SetInput(1, selection); #else extractSelection->SetInputData(1, selection); #endif extractSelection->Update(); neighborCellsMapper->SetInputConnection(extractSelection->GetOutputPort()); } vtkSmartPointer<vtkActor> neighborCellsActor = vtkSmartPointer<vtkActor>::New(); neighborCellsActor->SetMapper(neighborCellsMapper); neighborCellsActor->GetProperty()->SetColor(0,1,0); // Create a renderer, render window, and interactor vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); renderWindowInteractor->SetRenderWindow(renderWindow); // Add the actors to the scene renderer->AddActor(sphereActor); renderer->AddActor(mainCellActor); renderer->AddActor(neighborCellsActor); renderer->SetBackground(.3, .2, .1); // Background color dark red // Render and interact renderWindow->Render(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(CellEdgeNeighbors) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(CellEdgeNeighbors MACOSX_BUNDLE CellEdgeNeighbors.cxx) target_link_libraries(CellEdgeNeighbors ${VTK_LIBRARIES})
Download and Build CellEdgeNeighbors¶
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Click here to download CellEdgeNeighbors and its CMakeLists.txt file. Once the tarball CellEdgeNeighbors.tar has been downloaded and extracted,
cd CellEdgeNeighbors/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:
./CellEdgeNeighbors
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.