GetMiscCellData

VTKExamples/Cxx/PolyData/GetMiscCellData

Code

GetMiscCellData.cxx

#include <vtkSmartPointer.h>
#include <vtkCellData.h>
#include <vtkCellArray.h>
#include <vtkFloatArray.h>
#include <vtkTriangle.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkXMLPolyDataReader.h>

int main(int argc, char *argv[])
{
  // Parse command line arguments
  if(argc != 3)
  {
    std::cout << "Required arguments: Filename ArrayName" << std::endl;
    return EXIT_FAILURE;
  }

  // Get filename from command line
  std::string filename = argv[1]; //first command line argument

  // Get array name
  std::string arrayName = argv[2]; //second command line argument

  //read the file
  vtkSmartPointer<vtkXMLPolyDataReader> reader =
    vtkSmartPointer<vtkXMLPolyDataReader>::New();
  reader->SetFileName(filename.c_str());
  reader->Update();

  vtkPolyData* polydata = reader->GetOutput();

  // Get the number of cells in the polydata
  vtkIdType idNumCellsInFile = polydata->GetNumberOfCells();

  vtkSmartPointer<vtkFloatArray> array =
    vtkFloatArray::SafeDownCast(polydata->GetCellData()->GetArray(arrayName.c_str()));

  if(array)
  {
    std::cout << "Got array " << arrayName
              << " with " << idNumCellsInFile << " values"
              << std::endl;
    for(int i = 0; i < idNumCellsInFile; i++)
    {
      double value;
      value = array->GetValue(i);
      std::cout << i << ": " << value << std::endl;
    }
  }
  else
  {
    std::cout << "The file " << filename
              << " does not have a CellData array named " << arrayName
              << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(GetMiscCellData)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkIOXML QUIET)
if (NOT VTK_FOUND)
  message("Skipping GetMiscCellData: ${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(GetMiscCellData MACOSX_BUNDLE GetMiscCellData.cxx )
  target_link_libraries(GetMiscCellData PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(GetMiscCellData MACOSX_BUNDLE GetMiscCellData.cxx )
  target_link_libraries(GetMiscCellData PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS GetMiscCellData
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build GetMiscCellData

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

cd GetMiscCellData/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:

./GetMiscCellData

WINDOWS USERS

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