Class Name: Bordered Feature Face

Superclass - SEDRIS Abstract Base

Definition

The one-directional topological relationship between a Feature Edge and the ordered collection of Feature Faces that are bordered by it.

Primary Page in DRM Diagram:

• 12

Example

1. The Feature Edge that forms the boundary between two Feature Faces, one representing a field and the other representing a forest, would have a Bordered Feature Face object referencing those two Feature Faces. Note that the Feature Edge would also be referenced by each of the two Feature Faces via either an External Feature Face Ring or an Internal Feature Face Ring.

FAQs

When is a Bordered Feature Face object required?

A Feature Edge object is required to have a Bordered Feature Face component whenever it forms part of the boundary of one or more Feature Faces. At feature topology levels 0, 1, and 2, Feature Faces will be present only if they define the shape of an Areal Feature. Any Feature Edge that forms part of the boundary of one or more such Feature Faces is required to have a Bordered Feature Face component. At feature topology level 3, all Feature Edges must bound exactly 2 Feature Faces, and so all Feature Edges must have a Bordered Feature Face component. At feature topology level 4, Feature Edges are no longer required to bound Feature Faces, though most will, and these Feature Edges must have a Bordered Feature Face component. If a Feature Edge does not border any Feature Faces, it cannot have a Bordered Feature Face component.

Can the same Feature Face appear more than once in the collection of Feature Faces associated with a Bordered Feature Face?

Yes. At feature topology levels 3 or 4, if the Feature Edge of which the Bordered Feature Face is a component is contained within a single Feature Face, that Feature Face will appear twice is the collection of Feature Faces associated with the Bordered Feature Face object. Furthermore, in such a case, no other Feature Faces will appear in the collection of Feature Faces.

What is the relationship between the Bordered Feature Face class and the Feature Face Ring classes (Internal...) and External...)?

The Bordered Feature Face class and the Feature Face Ring classes form the two halves of the bidirectional topological relationship between Feature Edges and Feature Faces. Whenever a Feature Face appears in the collection of Feature Faces associated with the Bordered Feature Face component of a Feature Edge, that same Feature Edge must appear in the collection of Feature Edges associated with one of the Feature Face Ring components of that Feature Face, and vice versa.

Constraints

• Non Crossing Associations

Associated to (one-way)

• one or more {ordered} Feature Faces

Component of (one-way)

• one Feature Edge