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PointOccupancy

vtk-examples/Cxx/Points/PointOccupancy


Question

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Code

PointOccupancy.cxx

#include <vtkCamera.h>
#include <vtkDataSetMapper.h>
#include <vtkImageData.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointOccupancyFilter.h>
#include <vtkPointSource.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkThreshold.h>

#include <vtkBYUReader.h>
#include <vtkOBJReader.h>
#include <vtkPLYReader.h>
#include <vtkPolyDataReader.h>
#include <vtkSTLReader.h>
#include <vtkXMLPolyDataReader.h>

#include <vtksys/SystemTools.hxx>

namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(const char* fileName);
}

int main(int argc, char* argv[])
{
  auto polyData = ReadPolyData(argc > 1 ? argv[1] : "");

  int dimension = 128;
  vtkNew<vtkPointOccupancyFilter> occupancy;
  occupancy->SetInputData(polyData);
  occupancy->SetSampleDimensions(dimension, dimension, dimension);
  occupancy->SetOccupiedValue(255);
  occupancy->Update();

  vtkNew<vtkThreshold> threshold;
  threshold->SetInputConnection(occupancy->GetOutputPort());
  threshold->SetUpperThreshold(255);
  threshold->SetThresholdFunction(vtkThreshold::THRESHOLD_UPPER);
  threshold->AllScalarsOff();

  vtkNew<vtkDataSetMapper> mapper;
  mapper->SetInputConnection(threshold->GetOutputPort());
  mapper->ScalarVisibilityOff();

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);

  // Colors
  vtkNew<vtkNamedColors> nc;
  double flesh[3];
  nc->GetColorRGB("moccasin", flesh);
  actor->GetProperty()->SetColor(flesh);

  // Create graphics stuff
  //
  vtkNew<vtkRenderer> ren1;
  ren1->AddActor(actor);
  ren1->SetBackground(nc->GetColor3d("CornflowerBLue").GetData());

  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren1);
  renWin->SetSize(512, 512);
  renWin->SetWindowName("PointOccupancy");

  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  // Add the actors to the renderer, set the background and size
  //

  // Generate an interesting view
  //
  ren1->ResetCamera();
  ren1->GetActiveCamera()->Azimuth(120);
  ren1->GetActiveCamera()->Elevation(30);
  ren1->GetActiveCamera()->Dolly(1.25);
  ren1->ResetCameraClippingRange();

  renWin->Render();
  iren->Initialize();
  iren->Start();

  return EXIT_SUCCESS;
}

namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(const char* fileName)
{
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension =
      vtksys::SystemTools::GetFilenameExtension(std::string(fileName));
  if (extension == ".ply")
  {
    vtkNew<vtkPLYReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    vtkNew<vtkXMLPolyDataReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtk")
  {
    vtkNew<vtkPolyDataReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    vtkNew<vtkOBJReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    vtkNew<vtkSTLReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".g")
  {
    vtkNew<vtkBYUReader> reader;
    reader->SetGeometryFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    vtkNew<vtkMinimalStandardRandomSequence> randomSequence;
    randomSequence->SetSeed(8775070);

    vtkNew<vtkPointSource> points;
    points->SetNumberOfPoints(100000);
    points->SetRadius(10.0);
    double x, y, z;
    // random position
    x = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    y = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    z = randomSequence->GetRangeValue(-100, 100);
    randomSequence->Next();
    points->SetCenter(x, y, z);
    points->SetDistributionToShell();
    points->Update();
    polyData = points->GetOutput();
  }
  return polyData;
}
} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(PointOccupancy)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkFiltersPoints
  vtkFiltersSources
  vtkIOGeometry
  vtkIOLegacy
  vtkIOPLY
  vtkIOXML
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

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

Download and Build PointOccupancy

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

cd PointOccupancy/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:

./PointOccupancy

WINDOWS USERS

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