Contained Geometry Node

Class Name: Contained Geometry Node

A topological relationship between a Geometry Face and a Geometry Node, indicating that the Geometry Face contains the Geometry Node.

Consider a Geometry Face representing a lake, within which there is an island with a building on it. This building is represented topologically by a Geometry Node.
To indicate that the building exists within the boundary of the lake, so that the consumer does not have to spend time performing numerical comparisons, the data provider has given the Geometry Face a Contained Geometry Node component, which is in turn related to the Geometry Node, indicating that it is contained within the boundary of the lake.
(Note that the data provider may provide additional information and higher-level topology by providing the Geometry Node with a corresponding Contained Within Geometry Face component as well.)

When is a Contained Geometry Node object required?: At geometry topology levels 3 and 4, a Geometry Face object is required to have a Contained Geometry Node component for each Geometry Node that is located within its boundaries. At geometry topology levels 0 through 2, the Contained Geometry Node component is optional. Also, if a Geometry Face does not contain any Geometry Nodes within its boundaries, it must not have any Contained Geometry Node components.
Can the same Geometry Node be a component of more than one Contained Geometry Node object?: Yes. Since a Geometry Node can be located located within the boundaries of two Geometry Face, it may only be a component of two Contained Geometry Node objects.
What is the relationship between the Contained Geometry Node class and the Contained Within Geometry Face class?: The Contained Geometry Node class and the Contained Within Geometry Face class form the two halves of the bidirectional topological relationship between Geometry Faces and Geometry Nodes. Whenever a Geometry Node appears as a component of a Contained Geometry Node component of a Geometry Face, that same Geometry Face must be associated with a Contained Within Geometry Face component of that Geometry Node (and vice versa, if the topology level is 3 or more).