fix create_polyhedron code
@@ -487,7 +487,7 @@ class LevelGeometries:
if (a, b) in edges or (b, a) in edges:
new_edges.setdefault(a, deque()).append(b)
edges = new_edges
- double_points = [a for a, bs in edges.items() if len(bs) > 1]
+ double_points = set(a for a, bs in edges.items() if len(bs) > 1)
while edges:
new_ring = deque()
if double_points:
@@ -500,6 +500,7 @@ class LevelGeometries:
new_ring.append(start)
while start != last:
new_ring.append(last)
+ double_points.discard(last)
new_last = edges[last].pop()
if not edges[last]:
edges.pop(last)
