ThresholdPoints
VTKExamples/Cxx/PolyData/ThresholdPoints
Code¶
ThresholdPoints.cxx
#include <vtkVersion.h> #include <vtkIntArray.h> #include <vtkPoints.h> #include <vtkPolyData.h> #include <vtkPointData.h> #include <vtkSmartPointer.h> #include <vtkThresholdPoints.h> int main(int, char *[]) { vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); points->InsertNextPoint(0,0,0); points->InsertNextPoint(1,1,1); points->InsertNextPoint(2,2,2); points->InsertNextPoint(3,3,3); points->InsertNextPoint(4,4,4); std::cout << "There are " << points->GetNumberOfPoints() << " points before thresholding." << std::endl; //setup position index vtkSmartPointer<vtkIntArray> index = vtkSmartPointer<vtkIntArray>::New(); index->SetNumberOfComponents(1); index->SetName("index"); index->InsertNextValue(0); index->InsertNextValue(1); index->InsertNextValue(2); index->InsertNextValue(3); index->InsertNextValue(4); vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New(); polydata->SetPoints(points); polydata->GetPointData()->AddArray(index); vtkSmartPointer<vtkThresholdPoints> threshold = vtkSmartPointer<vtkThresholdPoints>::New(); #if VTK_MAJOR_VERSION <= 5 threshold->SetInput(polydata); #else threshold->SetInputData(polydata); #endif threshold->ThresholdByLower(2); threshold->SetInputArrayToProcess(0, 0, 0, vtkDataObject::FIELD_ASSOCIATION_POINTS, "index"); threshold->Update(); //vtkPolyData* thresholdedPolydata = threshold->GetOutput(); vtkPolyData* thresholdedPolydata = threshold->GetOutput(); std::cout << "There are " << thresholdedPolydata->GetNumberOfPoints() << " points after thresholding." << std::endl; for(vtkIdType i = 0; i < thresholdedPolydata->GetNumberOfPoints(); i++) { double p[3]; thresholdedPolydata->GetPoint(i,p); std::cout << "Point " << i << " : " << p[0] << " " << p[1] << " " << p[2] << std::endl; } return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ThresholdPoints) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ThresholdPoints MACOSX_BUNDLE ThresholdPoints.cxx) target_link_libraries(ThresholdPoints ${VTK_LIBRARIES})
Download and Build ThresholdPoints¶
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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 Some tarballs may be missing or out-of-date.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 ThresholdPoints and its CMakeLists.txt file. Once the tarball ThresholdPoints.tar has been downloaded and extracted,
cd ThresholdPoints/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:
./ThresholdPoints
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.