got cc working

surf/subd/cc.py

@@ -5,46 +5,45 @@ from surf.geometry import PolygonMesh, centroid
 
 def refine(mesh):
     new_vertices = list(mesh.vertices)
+
+    # this can be used to both get to fvid in new_vertices and to offest
+    # mesh.faces to be dealing with the fvid generated from that face
     f_vert_offset = len(new_vertices)
 
-    edge_vids_for_face = defaultdict(list)
+    # this doesn't need to be calculated, but it is conceptually convenient to
-    face_ids_for_v = defaultdict(list)
+    # have along the way. Alternatively one could get this by doing a:
+    # >>> [e + e_vert_offset for e in mesh.edges_for_face[fvid]
+    # (fvid for all faces)
+    evid_for_fvid = defaultdict(list)
 
-    # TODO: not completely populated yet:
     new_edges = []
-
-    # TODO: must be populated:
     new_faces = []
 
-    # For each face, add a face point
+    # For each face, add a face Vertex
-    for cur_face_id, cur_face in enumerate(mesh.faces):
+    for old_fid, old_face in enumerate(mesh.faces):
-        # Set each face point to be the centroid of all original points for the
+        # Set each face Vertex to be the centroid of all original Vertices for
-        # respective face.
+        # the respective face.
 
         # here we have already created a list that is a copy of the original
-        # verts. we append the new face points to that same list, and simply
+        # verts. we append the new face Vertices to that same list, and simply
-        # keep track of offsets into the new vert list ... see e_vert_offset
+        # keep track of offsets into the new vert list ... see f_vert_offset
-        # below
+        # above and e_vert_offset below
-        new_face_point = mesh.centroid(cur_face)
+        new_face_vertex = mesh.centroid(old_face)
-        new_vertices.append(new_face_point)
+        new_vertices.append(new_face_vertex)
-        for i in cur_face:
-            face_ids_for_v[i].append(cur_face_id)
 
+    # edge verts will be new_vertices[e_vert_offset:]. Also, this can be used
+    # to both get to evid in new_vertices and to offest mesh.edges to be
+    # dealing with the evid generated from that edge
     e_vert_offset = len(new_vertices)
 
-    # For each edge, add an edge point.
+    # For each edge, add an edge Vertex.
-    for old_edge_id, old_edge in enumerate(mesh.edges):
+    for old_eid, old_edge in enumerate(mesh.edges):
-        # make mapping from edge -> new_face_vert for later
-        old_face_ids_for_old_edge = mesh.faces_for_edge[old_edge_id]
-        for fid in old_face_ids_for_old_edge:
-            edge_vids_for_face[fid].append(old_edge_id)
-
         tmp_verts = []
 
-        # Set each edge point to be the average of the two neighbouring, (very
+        # Set each edge Vertex to be the average of the two neighbouring, (very
-        # recently calculated) face points ...
+        # recently calculated) face Vertices ...
         tmp_verts.extend([new_vertices[f + f_vert_offset]
-            for f in old_face_ids_for_old_edge])
+            for f in mesh.faces_for_edge[old_eid]])
 
         # ... and its two original endpoints.
         tmp_verts.extend([mesh.vertices[vid] for vid in old_edge])
@@ -52,25 +51,23 @@ def refine(mesh):
         # centroid == average
         new_vertices.append(centroid(tmp_verts))
 
-    # For each face point, add an edge connecting the new face point to each
+        # make mapping from evid -> fvid for later
-    # new edge point
+        for old_fid in mesh.faces_for_edge[old_eid]:
-    new_face_vert_ids = new_vertices[f_vert_offset:e_vert_offset]
+            fvid = old_fid + f_vert_offset
-    for trunc_vid in xrange(len(new_face_vert_ids)):
+            evid = old_eid + e_vert_offset
-        overall_vid = f_vert_offset + trunc_vid
+            evid_for_fvid[fvid].append(evid)
-        for edge_vid in edge_vids_for_face[trunc_vid]:
-            new_edges.append([edge_vid, overall_vid])
 
-    # For each original point P, move the original point to a new location
+    # For each original Vertex P, move the original Vertex to a new location
     # Here we mimic the F, R, and P spelling in the wiki article
     for old_vid in xrange(f_vert_offset):
-        # take the average F of all n face points for faces touching P ...
+        # take the average F of all n face Vertices for faces touching P ...
         F_verts = []
         for old_fid in mesh.faces_for_vert[old_vid]:
             F_verts.append(new_vertices[f_vert_offset + old_fid])
         F = centroid(F_verts)
 
-        # and take the average R of all n edge midpoints for edges touching P
+        # and take the average R of all n new edge Vertices for edges adjacent
-        # wiki is wrong ... it should be the edge points, not midpoints ...
+        # to P
         edges = [mesh.edges[eid] for eid in mesh.edges_for_vert[old_vid]]
         e_verts = []
         for edge in edges:
@@ -78,16 +75,39 @@ def refine(mesh):
         R = centroid(e_verts)
 
         # where each edge midpoint is the average of its two endpoint vertices.
-        # **Move** each original point to the point (or add it to new_verts)
+        # *Move* each original point to the point (or replace it in new_verts)
         new_vertex_point = (F + 2 * R
                               + (len(edges) - 3) * new_vertices[old_vid]
                             ) / len(edges)
         new_vertices[old_vid] = new_vertex_point
 
-        # Connect each new Vertex point to the new edge points of all original
+        # Connect each new Vertex point (with original id) to the new edge
-        # edges incident on the original vertex.
+        # points of all original edges incident on the original vertex.
-        for eid in mesh.edges_for_vert[old_vid]:
+        for old_eid in mesh.edges_for_vert[old_vid]:
-            new_edges.append([old_vid, eid])
+            new_edges.append([old_vid, old_eid + e_vert_offset])
+
+    # For each face point, add an edge connecting the new face point to each
+    # new edge point
+    for fvid, evids in evid_for_fvid.iteritems():
+        for evid in evids:
+            new_edges.append([fvid, evid])
+
+    # to define new faces need to know the following for each new face:
+    for fvid in xrange(f_vert_offset, e_vert_offset):
+        # new face_vid (1 vid)
+
+        # vid connected to fvid (iterate over, use 1 vid periteration)
+        connected_vids = mesh.faces[fvid - f_vert_offset]
+        evids_for_current_face = evid_for_fvid[fvid]
+        for connected_vid in connected_vids:
+            # evid connected to both the vid and the fvid (2 vids)
+            evids_for_vid = [e + e_vert_offset for e in
+                    mesh.edges_for_vert[connected_vid]]
+            assert len(evids_for_vid) == 3
+            common_ids = list(set(evids_for_vid) & set(evids_for_current_face))
+            assert len(common_ids) == 2
+            # then connect the (4) vids together ...
+            new_faces.append([fvid, common_ids[0], connected_vid, common_ids[1]])
 
     return PolygonMesh(vertices=new_vertices, edges=new_edges, faces=new_faces)