GeometryFilter

VTKExamples/Cxx/PolyData/GeometryFilter

Description

This example demonstrates how to convert an unstructured grid to a polydata. Currently nothing is done with the resulting polydata. If someone has a good data set that demonstrates the conversion, please let us know.

Code

GeometryFilter.cxx

#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkUnstructuredGrid.h>
#include <vtkCellArray.h>
#include <vtkGeometryFilter.h>
#include <vtkPointSource.h>

int main(int, char *[])
{ 
  vtkSmartPointer<vtkUnstructuredGrid> unstructuredGrid = 
    vtkSmartPointer<vtkUnstructuredGrid>::New();

  vtkSmartPointer<vtkGeometryFilter> geometryFilter = 
    vtkSmartPointer<vtkGeometryFilter>::New();
#if VTK_MAJOR_VERSION <= 5
  geometryFilter->SetInput(unstructuredGrid);
#else
  geometryFilter->SetInputData(unstructuredGrid);
#endif
  geometryFilter->Update(); 

  vtkPolyData* polydata = geometryFilter->GetOutput();

  std::cout << "Output has " << polydata->GetNumberOfPoints() << " points." << std::endl;

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(GeometryFilter)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(GeometryFilter MACOSX_BUNDLE GeometryFilter.cxx )

target_link_libraries(GeometryFilter ${VTK_LIBRARIES})

Download and Build GeometryFilter

Click here to download GeometryFilter and its CMakeLists.txt file. Once the tarball GeometryFilter.tar has been downloaded and extracted,

cd GeometryFilter/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:

./GeometryFilter

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.