VertexConnectivity
VTKExamples/Cxx/PolyData/VertexConnectivity
Description
The input must be only edges (i.e. vtkExtractEdges must be run).
Code
VertexConnectivity.cxx
#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkIdList.h>
#include <vtkPolyData.h>
#include <vtkCellData.h>
#include <vtkDoubleArray.h>
#include <vtkDataSet.h>
#include <vtkSphereSource.h>
#include <vtkTriangleFilter.h>
#include <vtkExtractEdges.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 <vtkVertexGlyphFilter.h>
vtkSmartPointer<vtkIdList> GetConnectedVertices(vtkSmartPointer<vtkPolyData> mesh, int id);
int main(int, char *[])
{
vtkSmartPointer<vtkSphereSource> sphereSource =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource->Update();
vtkSmartPointer<vtkTriangleFilter> triangleFilter =
vtkSmartPointer<vtkTriangleFilter>::New();
triangleFilter->SetInputConnection(sphereSource->GetOutputPort());
triangleFilter->Update();
vtkSmartPointer<vtkExtractEdges> extractEdges =
vtkSmartPointer<vtkExtractEdges>::New();
extractEdges->SetInputConnection(triangleFilter->GetOutputPort());
extractEdges->Update();
vtkSmartPointer<vtkPolyData> mesh = extractEdges->GetOutput();
vtkSmartPointer<vtkIdList> connectedVertices = GetConnectedVertices(mesh, 0);
vtkSmartPointer<vtkIdTypeArray> ids =
vtkSmartPointer<vtkIdTypeArray>::New();
ids->SetNumberOfComponents(1);
std::cout << "Connected vertices: ";
for(vtkIdType i = 0; i < connectedVertices->GetNumberOfIds(); i++)
{
std::cout << connectedVertices->GetId(i) << " ";
ids->InsertNextValue(connectedVertices->GetId(i));
}
std::cout << std::endl;
vtkSmartPointer<vtkDataSetMapper> connectedVertexMapper =
vtkSmartPointer<vtkDataSetMapper>::New();
{
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, extractEdges->GetOutputPort());
#if VTK_MAJOR_VERSION <= 5
extractSelection->SetInput(1, selection);
#else
extractSelection->SetInputData(1, selection);
#endif
extractSelection->Update();
vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
vtkSmartPointer<vtkVertexGlyphFilter>::New();
glyphFilter->SetInputConnection(extractSelection->GetOutputPort());
glyphFilter->Update();
connectedVertexMapper->SetInputConnection(glyphFilter->GetOutputPort());
}
vtkSmartPointer<vtkActor> connectedVertexActor =
vtkSmartPointer<vtkActor>::New();
connectedVertexActor->SetMapper(connectedVertexMapper);
connectedVertexActor->GetProperty()->SetColor(1,0,0);
connectedVertexActor->GetProperty()->SetPointSize(5);
vtkSmartPointer<vtkDataSetMapper> queryVertexMapper =
vtkSmartPointer<vtkDataSetMapper>::New();
{
vtkSmartPointer<vtkIdTypeArray> ids2 =
vtkSmartPointer<vtkIdTypeArray>::New();
ids2->SetNumberOfComponents(1);
ids2->InsertNextValue(0);
vtkSmartPointer<vtkSelectionNode> selectionNode =
vtkSmartPointer<vtkSelectionNode>::New();
selectionNode->SetFieldType(vtkSelectionNode::POINT);
selectionNode->SetContentType(vtkSelectionNode::INDICES);
selectionNode->SetSelectionList(ids2);
vtkSmartPointer<vtkSelection> selection =
vtkSmartPointer<vtkSelection>::New();
selection->AddNode(selectionNode);
vtkSmartPointer<vtkExtractSelection> extractSelection =
vtkSmartPointer<vtkExtractSelection>::New();
extractSelection->SetInputConnection(0, extractEdges->GetOutputPort());
#if VTK_MAJOR_VERSION <= 5
extractSelection->SetInput(1, selection);
#else
extractSelection->SetInputData(1, selection);
#endif
extractSelection->Update();
vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
vtkSmartPointer<vtkVertexGlyphFilter>::New();
glyphFilter->SetInputConnection(extractSelection->GetOutputPort());
glyphFilter->Update();
queryVertexMapper->SetInputConnection(glyphFilter->GetOutputPort());
}
vtkSmartPointer<vtkActor> queryVertexActor =
vtkSmartPointer<vtkActor>::New();
queryVertexActor->SetMapper(queryVertexMapper);
queryVertexActor->GetProperty()->SetColor(0,1,0);
queryVertexActor->GetProperty()->SetPointSize(5);
vtkSmartPointer<vtkDataSetMapper> sphereMapper =
vtkSmartPointer<vtkDataSetMapper>::New();
sphereMapper->SetInputConnection(extractEdges->GetOutputPort());
vtkSmartPointer<vtkActor> sphereActor =
vtkSmartPointer<vtkActor>::New();
sphereActor->SetMapper(sphereMapper);
//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(queryVertexActor);
renderer->AddActor(connectedVertexActor);
renderer->SetBackground(.3, .2, .1); // Background color dark red
//Render and interact
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
vtkSmartPointer<vtkIdList> GetConnectedVertices(vtkSmartPointer<vtkPolyData> mesh, int id)
{
vtkSmartPointer<vtkIdList> connectedVertices =
vtkSmartPointer<vtkIdList>::New();
//get all cells that vertex 'id' is a part of
vtkSmartPointer<vtkIdList> cellIdList =
vtkSmartPointer<vtkIdList>::New();
mesh->GetPointCells(id, cellIdList);
/*
cout << "Vertex 0 is used in cells ";
for(vtkIdType i = 0; i < cellIdList->GetNumberOfIds(); i++)
{
cout << cellIdList->GetId(i) << ", ";
}
cout << endl;
*/
for(vtkIdType i = 0; i < cellIdList->GetNumberOfIds(); i++)
{
//cout << "id " << i << " : " << cellIdList->GetId(i) << endl;
vtkSmartPointer<vtkIdList> pointIdList =
vtkSmartPointer<vtkIdList>::New();
mesh->GetCellPoints(cellIdList->GetId(i), pointIdList);
//cout << "End points are " << pointIdList->GetId(0) << " and " << pointIdList->GetId(1) << endl;
if(pointIdList->GetId(0) != id)
{
//cout << "Connected to " << pointIdList->GetId(0) << endl;
connectedVertices->InsertNextId(pointIdList->GetId(0));
}
else
{
//cout << "Connected to " << pointIdList->GetId(1) << endl;
connectedVertices->InsertNextId(pointIdList->GetId(1));
}
}
return connectedVertices;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(VertexConnectivity)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(VertexConnectivity MACOSX_BUNDLE VertexConnectivity.cxx)
target_link_libraries(VertexConnectivity ${VTK_LIBRARIES})
Download and Build VertexConnectivity
Click here to download VertexConnectivity and its CMakeLists.txt file. Once the tarball VertexConnectivity.tar has been downloaded and extracted,
cd VertexConnectivity/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:
./VertexConnectivity
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.