Contained Within Geometry Face

Class Name: Contained Within Geometry Face

A topological relationship between a Geometry Face and a Geometry Node, indicating that the Geometry Node is contained within the Geometry Face.

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 Node a Contained Within Geometry Face component, which is in turn related to the Geometry Face, indicating that the building 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 Face with a corresponding Contained Geometry Node component as well.

When is a Contained Within Geometry Face object required?: At geometry topology levels 3 and 4, a Geometry Node object is required to have a Contained Within Geometry Face component if it is located within the boundaries of a Geometry Face. At geometry topology levels 0 through 2, the Contained Within Geometry Face component is optional if the Geometry Node is located within a Geometry Face. If a Geometry Node is not located within the boundaries of a Geometry Face, it must not have a Contained Within Geometry Face component.
What is the relationship between the Contained Within Geometry Face class and the Contained Geometry Node class?: The Contained Within Geometry Face class and the Contained Geometry Node class form the two halves of the bidirectional topological relationship between Geometry Faces and Geometry Nodes. Whenever a Geometry Face is associated with the Contained Geometry Node component of a Geometry Node, that same Geometry Node must be the component of a Contained Geometry Node component of that Geometry Face and vice versa, if the topology level is 3 or higher.