fixed normal edge calculation for non-tri faces

examples/.ipynb_checkpoints/MixedValenceTest-checkpoint.ipynb

@@ -11,7 +11,7 @@
     "import numpy as np\n",
     "\n",
     "m = om.PolyMesh()\n",
-    "om.read_mesh(m, 'models/spot_quadrangulated.obj')\n",
+    "om.read_mesh(m, 'models/model_mixed_valence.obj')\n",
     "\n",
     "vertices = m.points()\n",
     "faces = m.face_vertex_indices()\n",
@@ -19,8 +19,17 @@
     "\n",
     "mesh = meshvis.Mesh(vertices, faces)\n",
     "mesh.colors = meshvis.FaceAttribute(np.random.rand(len(faces), 3))\n",
+    "mesh.normals = meshvis.calculateFaceNormals(vertices, faces)\n",
     "\n",
-    "meshvis.Context().draw(mesh).draw(meshvis.EdgeList(vertices, edges)).draw(meshvis.PointList(vertices), point_size=5).display()\n",
+    "normal_vis_verts, normal_vis_edges = meshvis.calculateNormalEdges(vertices, faces, mesh.normals, 1)\n",
+    "\n",
+    "ctx = meshvis.Context()\n",
+    "\n",
+    "ctx.draw(mesh).draw(meshvis.EdgeList(vertices, edges)).draw(meshvis.PointList(vertices, colors='#aaaaaa'), point_size=3)\n",
+    "\n",
+    "ctx.draw_edges(normal_vis_verts, normal_vis_edges)\n",
+    "\n",
+    "ctx.display()\n",
     "\n"
    ]
   }

examples/MixedValenceTest.ipynb

@@ -11,7 +11,7 @@
     "import numpy as np\n",
     "\n",
     "m = om.PolyMesh()\n",
-    "om.read_mesh(m, 'models/spot_quadrangulated.obj')\n",
+    "om.read_mesh(m, 'models/model_mixed_valence.obj')\n",
     "\n",
     "vertices = m.points()\n",
     "faces = m.face_vertex_indices()\n",
@@ -19,8 +19,17 @@
     "\n",
     "mesh = meshvis.Mesh(vertices, faces)\n",
     "mesh.colors = meshvis.FaceAttribute(np.random.rand(len(faces), 3))\n",
+    "mesh.normals = meshvis.calculateFaceNormals(vertices, faces)\n",
     "\n",
-    "meshvis.Context().draw(mesh).draw(meshvis.EdgeList(vertices, edges)).draw(meshvis.PointList(vertices), point_size=5).display()\n",
+    "normal_vis_verts, normal_vis_edges = meshvis.calculateNormalEdges(vertices, faces, mesh.normals, 1)\n",
+    "\n",
+    "ctx = meshvis.Context()\n",
+    "\n",
+    "ctx.draw(mesh).draw(meshvis.EdgeList(vertices, edges)).draw(meshvis.PointList(vertices, colors='#aaaaaa'), point_size=3)\n",
+    "\n",
+    "ctx.draw_edges(normal_vis_verts, normal_vis_edges)\n",
+    "\n",
+    "ctx.display()\n",
     "\n"
    ]
   }

examples/models/model_mixed_valence.obj

+# Blender v2.79 (sub 0) OBJ File: ''
+# www.blender.org
+v -1.000000 -1.000000 1.260390
+v -1.000000 1.000000 1.191139
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 -1.000000
+v -1.000000 0.000000 1.887504
+v 2.246086 -1.000000 1.000000
+v 2.246086 1.000000 1.000000
+v 2.246086 -1.000000 -1.000000
+v 2.246086 1.000000 -1.000000
+vn -1.0000 0.0000 0.0000
+vn 0.0000 0.0000 -1.0000
+vn 0.0000 1.0000 0.0000
+vn 0.2681 0.0167 0.9632
+vn 0.0000 -1.0000 0.0000
+vn 1.0000 0.0000 0.0000
+vn 0.0000 0.0000 1.0000
+s off
+f 1//1 9//1 2//1 4//1 3//1
+f 3//2 4//2 8//2 13//2 12//2 7//2
+f 8//3 6//3 11//3 13//3
+f 5//4 6//4 2//4 9//4 1//4
+f 3//5 7//5 5//5 1//5
+f 4//3 6//3 8//3
+f 4//3 2//3 6//3
+f 12//6 13//6 11//6 10//6
+f 6//7 5//7 10//7 11//7
+f 5//5 7//5 12//5 10//5

meshvis/mesh_helper.py

@@ -10,10 +10,8 @@ def calculateNormalEdges(vertices, face_indices, normals, length):
         resolved_normals = normals.values
         face_centers = []
         for face in face_indices:
-            v1 = np.array(vertices[face[0]])
-            v2 = np.array(vertices[face[1]])
-            v3 = np.array(vertices[face[2]])
-            face_centers.append((v1 + v2 + v3)/3)
+            face_vertices = vertices[face]
+            face_centers.append(np.average(face_vertices, axis=0, weights=face!=-1))
         vertices = face_centers
     else:
         resolved_normals = resolve_attributes(face_indices, [normals])[0]