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HighlightBadCells

vtk-examples/Cxx/PolyData/HighlightBadCells


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Question

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Code

HighlightBadCells.cxx

#include <vtkActor.h>
#include <vtkCellData.h>
#include <vtkDataSet.h>
#include <vtkDataSetMapper.h>
#include <vtkDoubleArray.h>
#include <vtkMeshQuality.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
#include <vtkThreshold.h>
#include <vtkTriangleFilter.h>
#include <vtkUnstructuredGrid.h>

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

  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->Update();

  vtkNew<vtkTriangleFilter> triangleFilter;
  triangleFilter->SetInputConnection(sphereSource->GetOutputPort());
  triangleFilter->Update();

  // Create a mapper and actor
  vtkNew<vtkDataSetMapper> sphereMapper;
  sphereMapper->SetInputConnection(triangleFilter->GetOutputPort());
  vtkNew<vtkActor> sphereActor;
  sphereActor->SetMapper(sphereMapper);
  sphereActor->GetProperty()->SetColor(
      colors->GetColor3d("MistyRose").GetData());

  vtkPolyData* mesh = triangleFilter->GetOutput();
  cout << "There are " << mesh->GetNumberOfCells() << " cells." << endl;

  vtkNew<vtkMeshQuality> qualityFilter;
  qualityFilter->SetInputData(mesh);
  qualityFilter->SetTriangleQualityMeasureToArea();
  qualityFilter->Update();

  vtkDataSet* qualityMesh = qualityFilter->GetOutput();
  auto qualityArray = dynamic_cast<vtkDoubleArray*>(
      qualityMesh->GetCellData()->GetArray("Quality"));

  cout << "There are " << qualityArray->GetNumberOfTuples() << " values."
       << endl;

  for (vtkIdType i = 0; i < qualityArray->GetNumberOfTuples(); i++)
  {
    double val = qualityArray->GetValue(i);
    cout << "value " << i << " : " << val << endl;
  }

  vtkNew<vtkThreshold> selectCells;
  //selectCells->ThresholdByLower(.02);
  selectCells->SetLowerThreshold(0.02);
  selectCells->SetThresholdFunction(vtkThreshold::THRESHOLD_LOWER);
  selectCells->SetInputArrayToProcess(0, 0, 0,
                                      vtkDataObject::FIELD_ASSOCIATION_CELLS,
                                      vtkDataSetAttributes::SCALARS);
  selectCells->SetInputData(qualityMesh);
  selectCells->Update();

  vtkUnstructuredGrid* ug = selectCells->GetOutput();

  // Create a mapper and actor
  vtkNew<vtkDataSetMapper> mapper;
  mapper->SetInputData(ug);

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetRepresentationToWireframe();
  actor->GetProperty()->SetLineWidth(5);
  actor->GetProperty()->SetColor(colors->GetColor3d("Red").GetData());

  // Create a renderer, render window, and interactor
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("HighlightBadCells");

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

  // Add the actors to the scene
  renderer->AddActor(actor);
  renderer->AddActor(sphereActor);
  renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());

  // Render and interact
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(HighlightBadCells)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersCore
  FiltersSources
  FiltersVerdict
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "HighlightBadCells: 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(HighlightBadCells MACOSX_BUNDLE HighlightBadCells.cxx )
  target_link_libraries(HighlightBadCells PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS HighlightBadCells
  MODULES ${VTK_LIBRARIES}
)

Download and Build HighlightBadCells

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

cd HighlightBadCells/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:

./HighlightBadCells

WINDOWS USERS

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