CleanPolyData

VTKExamples/Cxx/PolyData/CleanPolyData

Description

When a cube is created, it has 24 vertices (4 for each face). This is done because the normal at each face is very different. Often we would want a cube to only have 8 vertices. The vtkCleanPolyData filter removes coincident points, resulting in the cube we would expect.

Code

CleanPolyData.cxx

#include <vtkSmartPointer.h>
#include <vtkCubeSource.h>
#include <vtkPolyData.h>
#include <vtkCleanPolyData.h>

int main(int, char *[])
{
  vtkSmartPointer<vtkCubeSource> cubeSource = 
    vtkSmartPointer<vtkCubeSource>::New();
  cubeSource->Update();

  std::cout << "Input cube has " << cubeSource->GetOutput()->GetNumberOfPoints() 
    << " vertices." << std::endl;

  vtkSmartPointer<vtkCleanPolyData> cleanPolyData = 
      vtkSmartPointer<vtkCleanPolyData>::New();
  cleanPolyData->SetInputConnection(cubeSource->GetOutputPort());
  cleanPolyData->Update();

  std::cout << "Cleaned cube has " << cleanPolyData->GetOutput()->GetNumberOfPoints() 
    << " vertices." << std::endl;

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(CleanPolyData)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkFiltersSources QUIET)
if (NOT VTK_FOUND)
  message("Skipping CleanPolyData: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(CleanPolyData MACOSX_BUNDLE CleanPolyData.cxx )
  target_link_libraries(CleanPolyData PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(CleanPolyData MACOSX_BUNDLE CleanPolyData.cxx )
  target_link_libraries(CleanPolyData PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS CleanPolyData
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build CleanPolyData

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

cd CleanPolyData/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:

./CleanPolyData

WINDOWS USERS

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