PolyDataConnectivityFilter LargestRegion
VTKExamples/Cxx/PolyData/PolyDataConnectivityFilter_LargestRegion
Description
This example keeps the largest connected region of a mesh. Note that this is based on the number of points, not the actual area of the region.
- Contributed by: Jinyoung Hwang
Code
PolyDataConnectivityFilter_LargestRegion.cxx
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataConnectivityFilter.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkAppendPolyData.h>
int main(int, char *[])
{
// Small sphere
vtkSmartPointer<vtkSphereSource> sphereSource1 =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource1->Update();
// Large sphere
vtkSmartPointer<vtkSphereSource> sphereSource2 =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource2->SetRadius(10);
sphereSource2->SetCenter(25,0,0);
sphereSource2->SetThetaResolution(10);
sphereSource2->SetPhiResolution(10);
sphereSource2->Update();
vtkSmartPointer<vtkAppendPolyData> appendFilter =
vtkSmartPointer<vtkAppendPolyData>::New();
appendFilter->AddInputConnection(sphereSource1->GetOutputPort());
appendFilter->AddInputConnection(sphereSource2->GetOutputPort());
appendFilter->Update();
vtkSmartPointer<vtkPolyDataConnectivityFilter> connectivityFilter =
vtkSmartPointer<vtkPolyDataConnectivityFilter>::New();
connectivityFilter->SetInputConnection(appendFilter->GetOutputPort());
connectivityFilter->SetExtractionModeToLargestRegion();
connectivityFilter->Update();
// Create a mapper and actor for original data
vtkSmartPointer<vtkPolyDataMapper> originalMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
originalMapper->SetInputConnection(appendFilter->GetOutputPort());
originalMapper->Update();
vtkSmartPointer<vtkActor> originalActor =
vtkSmartPointer<vtkActor>::New();
originalActor->SetMapper(originalMapper);
// Create a mapper and actor for extracted data
vtkSmartPointer<vtkPolyDataMapper> extractedMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
extractedMapper->SetInputConnection(connectivityFilter->GetOutputPort());
extractedMapper->Update();
vtkSmartPointer<vtkActor> extractedActor =
vtkSmartPointer<vtkActor>::New();
extractedActor->GetProperty()->SetColor(1,0,0);
extractedActor->SetMapper(extractedMapper);
// Visualization
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(originalActor);
renderer->AddActor(extractedActor);
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> interactor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow(renderWindow);
interactor->Initialize();
interactor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(PolyDataConnectivityFilter_LargestRegion)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(PolyDataConnectivityFilter_LargestRegion MACOSX_BUNDLE PolyDataConnectivityFilter_LargestRegion.cxx)
target_link_libraries(PolyDataConnectivityFilter_LargestRegion ${VTK_LIBRARIES})
Download and Build PolyDataConnectivityFilter_LargestRegion
Click here to download PolyDataConnectivityFilter_LargestRegion and its CMakeLists.txt file. Once the tarball PolyDataConnectivityFilter_LargestRegion.tar has been downloaded and extracted,
cd PolyDataConnectivityFilter_LargestRegion/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:
./PolyDataConnectivityFilter_LargestRegion
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.