MiscPointData

#include <vtkFloatArray.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNew.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkXMLPolyDataReader.h>

#include <iostream>
#include <string>

int main(int argc, char* argv[])
{
  // Parse command line arguments.
  if (argc != 2)
  {
    std::cout << "Required arguments: Filename e.g. cowHead.vtp" << std::endl;
    return EXIT_FAILURE;
  }

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

  // Read the file
  vtkNew<vtkXMLPolyDataReader> reader;
  std::cout << "Reading " << filename << std::endl;
  reader->SetFileName(filename.c_str());
  reader->Update();

  // Extract the polydata.
  auto polydata = reader->GetOutput();

  // Get the number of points in the polydata.
  vtkIdType idNumPointsInFile = polydata->GetNumberOfPoints();

  // Add distances to each point
  vtkNew<vtkFloatArray> distances;
  distances->SetNumberOfComponents(1);
  distances->SetName("Distances");

  vtkNew<vtkMinimalStandardRandomSequence> rng;
  rng->SetSeed(8775070);
  // rng->SetSeed(0);

  for (vtkIdType i = 0; i < idNumPointsInFile; i++)
  {
    distances->InsertNextValue(rng->GetRangeValue(0.0, 1.0));
    rng->Next();
  }

  polydata->GetPointData()->AddArray(distances);

  return EXIT_SUCCESS;
}

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(MiscPointData)

find_package(VTK COMPONENTS 
)

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

cd MiscPointData/build

cmake ..

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

make

./MiscPointData