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CellCenters

vtk-examples/Cxx/PolyData/CellCenters


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See (Java)

Question

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Code

CellCenters.cxx

#include <vtkActor.h>
#include <vtkCellCenters.h>
#include <vtkDataSetMapper.h>
#include <vtkImageData.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Create an image data
  vtkNew<vtkImageData> imageData;

  // Specify the size of the image data
  imageData->SetDimensions(3, 3, 2);
  imageData->SetSpacing(1.0, 1.0, 1.0);
  imageData->SetOrigin(0.0, 0.0, 0.0);

  vtkNew<vtkCellCenters> cellCentersFilter;
  cellCentersFilter->SetInputData(imageData);
  cellCentersFilter->VertexCellsOn();
  cellCentersFilter->Update();

  // Access the cell centers
  for (vtkIdType i = 0; i < cellCentersFilter->GetOutput()->GetNumberOfPoints();
       i++)
  {
    double p[3];
    cellCentersFilter->GetOutput()->GetPoint(i, p);
    cout << "Point " << i << " : " << p[0] << " , " << p[1] << " , " << p[2]
         << endl;
  }

  // Display the cell centers
  vtkNew<vtkDataSetMapper> centerMapper;
  centerMapper->SetInputConnection(cellCentersFilter->GetOutputPort());
  vtkNew<vtkActor> centerActor;
  centerActor->SetMapper(centerMapper);
  centerActor->GetProperty()->SetPointSize(5);
  centerActor->GetProperty()->SetColor(
      colors->GetColor3d("MistyRose").GetData());

  vtkNew<vtkDataSetMapper> mapper;
  mapper->SetInputData(imageData);

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetRepresentationToWireframe();
  actor->GetProperty()->SetColor(colors->GetColor3d("Gold").GetData());

  vtkNew<vtkRenderWindow> renderWindow;

  vtkNew<vtkRenderer> renderer;

  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("CellCenters");

  renderer->AddActor(actor);
  renderer->AddActor(centerActor);

  renderer->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());
  renderer->ResetCamera();

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(CellCenters)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping CellCenters: ${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(CellCenters MACOSX_BUNDLE CellCenters.cxx )
  target_link_libraries(CellCenters PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(CellCenters MACOSX_BUNDLE CellCenters.cxx )
  target_link_libraries(CellCenters PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS CellCenters
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build CellCenters

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

cd CellCenters/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:

./CellCenters

WINDOWS USERS

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