Rule Name: Contained Node Restrictions

Definition

1. At feature topology levels 3 and 4, a Feature Face object must have a Contained Feature Node component for each Feature Node that is located within its boundaries, and a Feature Node object must have a Contained Within Feature Face component if it is located within the boundaries of a Feature Face.

   Similarly, at geometry topology levels 3 and 4, a Geometry Face object must have a Contained Geometry Node component for each Geometry Node that is located within its boundaries, and a Geometry Node object must have a Contained Within Geometry Face component if it is located within the boundaries of a Geometry Face.

2. If a Feature Face does not contain any Feature Nodes within its boundaries, it must not have any Contained Feature Node components, and if a Feature Node is not located within the boundaries of a Feature Face, it must not have a Contained Within Feature Face component.

   Similarly, if a Geometry Face does not contain any Geometry Nodes within its boundaries, it must not have any Contained Geometry Node components, and if a Geometry Node is not located within the boundaries of a Geometry Face, it must not have a Contained Within Geometry Face component.

3. If a Feature Node is part of the Contained Feature Node of a Feature Face, then that same Feature Face must be associated with a Contained Within Feature Face component of that Feature Node, and vice versa.

   Similarly, if a Geometry Node is part of the Contained Geometry Node of a Geometry Face, then that same Geometry Face must be associated with a Contained Within Geometry Face component of that Geometry Node, and vice versa.

Rationale

Contained Feature Node is the one-directional topological relationship between a Feature Face and a Feature Node that is contained within its boundaries; if there are no Feature Nodes within the Feature Face, by definition there should not be a Contained Feature Node on that face.

Contained Geometry Node is the one-directional topological relationship between a Geometry Face and a Geometry Node that is contained within its boundaries; if there are no Geometry Nodes within the Geometry Face, by definition there should not be a Contained Geometry Node on that face.

Example

1. Consider a Feature Face X that contains a Feature Node A, where X is part of the Topology Hierarchy of a Classification Related Features with SE_LEVEL_4_FEATURE_TOPOLOGY. X must have a Contained Feature Node in order to be valid.

2. Consider Feature Face Y that does not contain any Feature Nodes. If Y is mistakenly created with a Contained Feature Node, then Y is invalid since the Contained Feature Node implies that Y does contain some Feature Node.

3. Consider Geometry Face Y that does not contain any Geometry Nodes. If Y is mistakenly created with a Contained Geometry Node, then Y is invalid since the Contained Geometry Node implies that Y does contain some Geometry Node.

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