Abstract Class Name: Feature Face Ring

Superclass - SEDRIS Abstract Base

Subclasses

• External Feature Face Ring
• Internal Feature Face Ring

Definition

The one-directional topological relationship between a Feature Face and the ordered collection of one or more Feature Edges that define one of its boundaries (outer or inner).

Primary Page in DRM Diagram:

• 12

Example

1. The outer boundary of a Regular Feature Face representing a lake is defined by a single Feature Edge. This Feature Edge will be the sole component of the External Feature Face Ring component of the Regular Feature Face. Another Regular Feature Face represents an island in the lake. Its boundary is also defined by a single Feature Edge. This second Feature Edge will be the sole component of an Internal Feature Face Ring component of the Regular Feature Face that represents the lake, and will also be the sole component of the External Feature Face Ring of the Regular Feature Face that represents the island.

                  <Regular Feature Face> (lake)
                             <>
              ----------------------------------
              |                                |
              |                                |
       <External Feature Face Ring>    <Internal Feature Face Ring>
             <>                               <>
              |                                |
              |-<Feature Ring Edge Direction>  |-<Feature Ring Edge Direction>
              |                                |
              |                                |
       <Feature Edge> (lake shore)      <Feature Edge> (island shore)
   

FAQs

When are Feature Face Ring objects required?

All Feature Face objects are required to have at least one Feature Face Ring component, regardless of the feature topology level. A Regular Feature Face must have an External Feature Face Ring, which defines its outer boundary, and may have zero or more Internal Feature Face Rings, which define inner boundaries (i.e., "holes") within the Feature Face. A Universal Feature Face has no External Feature Face Ring, but will have one or more Internal Feature Face Rings.

Can the same Feature Edge appear more than once in the collection of Feature Edges that are the components of a Feature Face Ring?

Yes. A Feature Edge can appear up to twice in a Feature Face Ring, once with each orientation.

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

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

Constraints

• Feature Face Ring Edge Consistency

Composed of (one-way)

• one or more {ordered} Feature Edges through Feature Ring Edge Directions