ENH: Add new example MassProperties

src/Cxx.md

@@ -563,7 +563,7 @@ This section includes vtkImageData vtkStructuredGrid and vtkRectilinearGrid.
 [Delaunay2D](/Cxx/Filtering/Delaunay2D) | vtkDelaunay2D | Perform a 2D Delaunay triangulation on a point set.
 [DetermineActorType](/Cxx/Utilities/DetermineActorType) | vtkActor vtkActorCollection |Determine the type of an actor.
 [DiscretizableColorTransferFunction](/Cxx/Utilities/DiscretizableColorTransferFunction) | vtkDiscretizableColorTransferFunction |Discretizable Color Transfer Function.
-[ExtractFaces](/Cxx/Utilities/ExtractFaces) | vtkCellIterator | Extract faces from vtkUnstructuredGrid.
+[ExtractFaces](/Cxx/Utilities/ExtractFaces) | vtkCellIterator | Extract faces froam vtkUnstructuredGrid.
 [FileOutputWindow](/Cxx/Utilities/FileOutputWindow) | vtkFileOutputWindow | Write errors to a log file  instead of the screen.
 [FilenameFunctions](/Cxx/Utilities/FilenameFunctions) | vtkDirectory vtksys/SystemTools | Do things like get the file extension, strip the file extension, etc.
 [FilterSelfProgress](/Cxx/Developers/FilterSelfProgress) |  |Monitor a filters progress.
@@ -573,6 +573,7 @@ This section includes vtkImageData vtkStructuredGrid and vtkRectilinearGrid.
 [GetClassName](/Cxx/Utilities/GetClassName) | GetClassName() |Determine the type of a VTK variable.
 [GetDataRoot](/Cxx/Utilities/GetDataRoot) | vtkTesting | Find the path of VTK_DATA_ROOT.
 [LUTUtilities](/Cxx/Utilities/LUTUtilities) | vtkLookupTable vtkColorSeries | A utility class for vtkLookupTable allowing you to output the table contents or to compare tables.
+[MassProperties](/Cxx/Utilities?MassProperties) | vtkMassProperties | Compute volume and surface area of a closed, triangulated mesh.
 [MultipleRenderWindows](/Cxx/Visualization/MultipleRenderWindows) | vtkRenderWindow | Multiple Render Windows
 [MultipleViewports](/Cxx/Visualization/MultipleViewports) | vtkRenderer::SetViewPort |Multiple Viewports.
 [OffScreenRendering](/Cxx/Utilities/OffScreenRendering) | vtkImagingFactory vtkGraphicsFactory |Off Screen Rendering.

src/Cxx/Utilities/MassProperties.cxx

+#include <vtkSmartPointer.h>
+#include <vtkMassProperties.h>
+#include <vtkTriangleFilter.h>
+#include <vtkFillHolesFilter.h>
+#include <vtkPolyDataNormals.h>
+
+#include <vtkBYUReader.h>
+#include <vtkOBJReader.h>
+#include <vtkPLYReader.h>
+#include <vtkPolyDataReader.h>
+#include <vtkSTLReader.h>
+#include <vtkXMLPolyDataReader.h>
+#include <vtkSphereSource.h>
+#include <vtksys/SystemTools.hxx>
+
+namespace
+{
+vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName);
+}
+
+int main (int argc, char *argv[])
+{
+  vtkSmartPointer<vtkPolyData> polyData = ReadPolyData(argc > 1 ? argv[1] : "");;
+
+
+  vtkSmartPointer<vtkFillHolesFilter> fillHolesFilter =
+    vtkSmartPointer<vtkFillHolesFilter>::New();
+  fillHolesFilter->SetInputData(polyData);
+  fillHolesFilter->SetHoleSize(1000.0);
+
+  vtkSmartPointer<vtkTriangleFilter> triangleFilter =
+    vtkSmartPointer<vtkTriangleFilter>::New();
+  triangleFilter->SetInputConnection(fillHolesFilter->GetOutputPort());
+
+  // Make the triangle windong order consistent
+  vtkSmartPointer<vtkPolyDataNormals> normals =
+    vtkSmartPointer<vtkPolyDataNormals>::New();
+  normals->SetInputConnection(triangleFilter->GetOutputPort());
+  normals->ConsistencyOn();
+  normals->SplittingOff();
+
+  vtkSmartPointer<vtkMassProperties> massProperties =
+    vtkSmartPointer<vtkMassProperties>::New();
+  massProperties->SetInputConnection(normals->GetOutputPort());
+  massProperties->Update();
+  std::cout << "Volume: " << massProperties->GetVolume() << std::endl
+            << "    VolumeX: " << massProperties->GetVolumeX() << std::endl
+            << "    VolumeY: " << massProperties->GetVolumeY() << std::endl
+            << "    VolumeZ: " << massProperties->GetVolumeZ() << std::endl
+            << "Area:   " << massProperties->GetSurfaceArea() << std::endl
+            << "    MinCellArea: " << massProperties->GetMinCellArea() << std::endl
+            << "    MinCellArea: " << massProperties->GetMaxCellArea() << std::endl
+            << "NormalizedShapeIndex: " << massProperties->GetNormalizedShapeIndex() << std::endl;
+
+  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")
+  {
+    vtkSmartPointer<vtkPLYReader> reader =
+      vtkSmartPointer<vtkPLYReader>::New();
+    reader->SetFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else if (extension == ".vtp")
+  {
+    vtkSmartPointer<vtkXMLPolyDataReader> reader =
+      vtkSmartPointer<vtkXMLPolyDataReader>::New();
+    reader->SetFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else if (extension == ".obj")
+  {
+    vtkSmartPointer<vtkOBJReader> reader =
+      vtkSmartPointer<vtkOBJReader>::New();
+    reader->SetFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else if (extension == ".stl")
+  {
+    vtkSmartPointer<vtkSTLReader> reader =
+      vtkSmartPointer<vtkSTLReader>::New();
+    reader->SetFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else if (extension == ".vtk")
+  {
+    vtkSmartPointer<vtkPolyDataReader> reader =
+      vtkSmartPointer<vtkPolyDataReader>::New();
+    reader->SetFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else if (extension == ".g")
+  {
+    vtkSmartPointer<vtkBYUReader> reader =
+      vtkSmartPointer<vtkBYUReader>::New();
+    reader->SetGeometryFileName (fileName);
+    reader->Update();
+    polyData = reader->GetOutput();
+  }
+  else
+  {
+    vtkSmartPointer<vtkSphereSource> source =
+      vtkSmartPointer<vtkSphereSource>::New();
+    source->SetPhiResolution(51);
+    source->SetThetaResolution(51);
+    source->Update();
+    polyData = source->GetOutput();
+  }
+  return polyData;
+}
+}

src/Cxx/Utilities/MassProperties.md

+### Description
+This example uses vtkMassProperties to compute the volume of a closed mesh. vtkmassProperties requires triangles with consistent ordering. This example uses vtkFillHolesFilter and vtkTriangles to ensure a closed, triangulated mseh.
+
+If run wth no argumnets, a vtkSphereSource generates the vtkPolyData. Of given a file containung vtkPolyData, it computes that data's volume and surface area.
+
+!!! cite
+   [(Alyassin A.M. et al, "Evaluation of new algorithms for the interactive measurement of surface area and volume", Med Phys 21(6) 1994.)](https://www.researchgate.net/profile/Abdalmajeid_Alyassin/publication/15264446_Evaluation_of_new_algorithms_for_the_interactive_measurement_of_surface_area_and_volume/links/5497dff10cf29b944826369a.pdf)
+