Aggregate (Organizing) Classes Fields: Feature Topology Level
Level 0
- Spaghetti. There’s topology here, but that’s all we know.
Level 1
- Each node corresponds to a unique location in space.
Level 2
- Edges intersect only at nodes.
Level 3
- Faces may not intersect except at edges, and must form a complete surface.
- <Contained Within Feature Face>, <Contained Feature Node>
Level 4
- <Location 3Ds> are required, and at least one edge must be a meeting place for more than 2 faces.