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CleanPolyData

vtk-examples/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.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

CleanPolyData.cxx

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

int main(int, char*[])
{
  vtkNew<vtkCubeSource> cubeSource;
  cubeSource->Update();

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

  vtkNew<vtkCleanPolyData> cleanPolyData;
  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 3.12 FATAL_ERROR)

project(CleanPolyData)

find_package(VTK COMPONENTS 
  CommonCore
  CommonDataModel
  FiltersCore
  FiltersSources
  QUIET
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "CleanPolyData: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
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}
)

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.