Started adding connectivity generation

- also added a test file in the blender folder

surf/geometry.py

@@ -175,25 +175,30 @@ class PolygonMesh(object):
     @property
     def edges_for_face(self):
         """returns a list of edge indices for a given face index."""
+        # XXX
         if self._edges_for_face is None:
-            # TODO: eventually support generating this ourselves ...
-            raise NotImplementedError
+            self._edges_for_face = [[] for i in range(len(self.faces))]
+
         return self._edges_for_face
 
     @property
     def edges_for_vert(self):
         """returns a list of edge indices for a given vertex index."""
         if self._edges_for_vert is None:
-            # TODO: eventually support generating this ourselves ...
-            raise NotImplementedError
+            self._edges_for_vert = [[] for i in range(len(self.vertices))]
+            for i, edge in enumerate(self.edges):
+                for vid in edge:
+                    self._edges_for_vert[vid].append(i)
         return self._edges_for_vert
 
     @property
     def faces_for_vert(self):
         """returns a list of face indices for a given vert index."""
         if self._faces_for_vert is None:
-            # TODO: eventually support generating this ourselves ...
-            raise NotImplementedError
+            self._faces_for_vert = [[] for i in range(len(self.vertices))]
+            for i, face in enumerate(self.faces):
+                for vid in face:
+                    self._faces_for_vert[vid].append(i)
         return self._faces_for_vert
 
     def __unicode__(self):