Script to create Menger sponge

src/Mod/Mesh/App/Core/Degeneration.cpp

@@ -380,6 +380,30 @@ bool MeshFixDuplicateFacets::Fixup()
 
 // ----------------------------------------------------------------------
 
+bool MeshEvalInternalFacets::Evaluate()
+{
+    _indices.clear();
+    unsigned long uIndex=0;
+    const MeshFacetArray& rFaces = _rclMesh.GetFacets();
+
+    // get all facets
+    std::set<FaceIterator, MeshFacet_Less > aFaceSet;
+    MeshFacetArray::_TConstIterator first = rFaces.begin();
+    for (MeshFacetArray::_TConstIterator it = rFaces.begin(); it != rFaces.end(); ++it, uIndex++) {
+        std::pair<std::set<FaceIterator, MeshFacet_Less>::iterator, bool>
+        pI = aFaceSet.insert(it);
+        if (!pI.second) {
+            // collect both elements
+            _indices.push_back(*pI.first - first);
+            _indices.push_back(uIndex);
+        }
+    }
+
+    return _indices.empty();
+}
+
+// ----------------------------------------------------------------------
+
 bool MeshEvalDegeneratedFacets::Evaluate()
 {
   MeshFacetIterator it(_rclMesh);

src/Mod/Mesh/App/Core/Degeneration.h

@@ -188,6 +188,35 @@ public:
   bool Fixup ();
 };
 
+/**
+ * The MeshEvalInternalFacets class identifies internal facets of a volume mesh.
+ * @author Werner Mayer
+ */
+class MeshExport MeshEvalInternalFacets : public MeshEvaluation
+{
+public:
+  /**
+   * Construction.
+   */
+  MeshEvalInternalFacets (const MeshKernel &rclM) : MeshEvaluation( rclM ) { }
+  /** 
+   * Destruction.
+   */
+  ~MeshEvalInternalFacets () { }
+  /** 
+   * Identifiy internal facets.
+   */
+  bool Evaluate ();
+  /**
+   * Return the indices.
+   */
+  const std::vector<unsigned long>& GetIndices() const
+  { return _indices; }
+
+private:
+    std::vector<unsigned long> _indices;
+};
+
 /**
  * The MeshEvalDegeneratedFacets class searches for degenerated facets. A facet is degenerated either if its points
  * are collinear, i.e. they lie on a line or two points are coincident. In the latter case these points are duplicated.

src/Mod/Mesh/App/MeshPy.xml

@@ -127,6 +127,16 @@ Example:
 				<UserDocu>Remove a list of facet indices from the mesh</UserDocu>
 			</Documentation>
 		</Methode>
+		<Methode Name="getInternalFacets" Const="true">
+			<Documentation>
+				<UserDocu>Builds a list of facet indices with triangles that are inside a volume mesh</UserDocu>
+			</Documentation>
+		</Methode>
+		<Methode Name="rebuildNeighbourHood">
+			<Documentation>
+				<UserDocu>Repairs the neighbourhood which might be broken</UserDocu>
+			</Documentation>
+		</Methode>
 		<Methode Name="addMesh">
 			<Documentation>
 				<UserDocu>Combine this mesh with another mesh.</UserDocu>

src/Mod/Mesh/App/MeshPyImp.cpp

@@ -36,6 +36,7 @@
 #include "MeshProperties.h"
 #include "Core/Algorithm.h"
 #include "Core/Iterator.h"
+#include "Core/Degeneration.h"
 #include "Core/Elements.h"
 #include "Core/Grid.h"
 #include "Core/MeshKernel.h"
@@ -581,6 +582,35 @@ PyObject* MeshPy::removeFacets(PyObject *args)
     Py_Return;
 }
 
+PyObject* MeshPy::getInternalFacets(PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, ""))
+        return 0;
+
+    const MeshCore::MeshKernel& kernel = getMeshObjectPtr()->getKernel();
+    MeshCore::MeshEvalInternalFacets eval(kernel);
+    eval.Evaluate();
+
+    const std::vector<unsigned long>& indices = eval.GetIndices();
+    Py::List ary(indices.size());
+    Py::List::size_type pos=0;
+    for (std::vector<unsigned long>::const_iterator it = indices.begin(); it != indices.end(); ++it) {
+        ary[pos++] = Py::Long(*it);
+    }
+
+    return Py::new_reference_to(ary);
+}
+
+PyObject* MeshPy::rebuildNeighbourHood(PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, ""))
+        return 0;
+
+    MeshCore::MeshKernel& kernel = getMeshObjectPtr()->getKernel();
+    kernel.RebuildNeighbours();
+    Py_Return;
+}
+
 PyObject*  MeshPy::addMesh(PyObject *args)
 {
     PyObject* mesh;