Abstract Class Name: Feature Topology Hierarchy

Superclass - <SEDRIS Abstract Base>

Subclasses

• <Perimeter Related Feature Topology>
• <Spatial Index Related Feature Topology>
• <Union Of Feature Topology>

Definition

An instance of this DRM class specifies a spatially organized hierarchical collection of <Feature Topology> instances, which includes all the <Feature Topology> instances that lie within a defined spatial extent, and are components of a single <Aggregate Feature> instance.

Primary Page in DRM Diagram:

• 11

Secondary Pages in DRM Diagram:

• 8
• 23

Example

1. The set of all <Feature Topology> instances contained within an independent topological surface, organized into a collection of regularly or irregularly shaped tiles.

FAQs

What is the purpose of this class?

This class allows <Feature Topology> instances to be spatially organized using different methods. It ensures that all <Feature Topology> instances, particularly those that are not directly associated with any <Feature Representation>, have at least one containing object.

Why not restrict <Feature Topology Hierarchy> to be a component of just <Environment Root> and <Model> - placing Topology as an organizing principle on par with <Geometry Representation> organizations and <Feature Representation> organizations?

It shall be possible to spatially organize the topology of every "topological surface". A "topological surface" is not necessarily "rooted at" an <Environment Root> or a <Model> instance. In general, many different "topological surfaces" may exist within a <Environment Root> or a <Model>.

Constraints

• <<Publishable Object>>

Component of (two-way)

• zero or more <Aggregate Feature> instances

Inherited Field Elements

Field Elements

Notes

Fields Notes

feature_topology_level

 The feature_topology_level field specifies the level of
 feature topology that is present within the hierarchy
 represented by the given <Feature Topology Hierarchy>
 instance.