getEdges.py

F = meshes[0]["Faces"].copy().sort(1)
num_faces = F.shape[0]

edges = {}
for i in range(num_faces):
    edges.setdefault(tuple(F[i,:2]),    []).append(i)
    edges.setdefault(tuple(F[i,1:3]),   []).append(i)
    edges.setdefault(tuple(F[i,[0,2]]), []).append(i)

neighbours = np.zeros((num_faces, 3), dtype=np.uint32)
idx        = np.zeros((num_faces),    dtype=np.uint32)

for ef in edges.values():
    neighbours[ef[0], idx[ef[0]]] = ef[1]
    neighbours[ef[1], idx[ef[1]]] = ef[0]
    idx[ef[0]] += 1
    idx[ef[1]] += 1