The SEDRIS Data Representation Model
APPENDIX A - Classes
Feature Topology Hierarchy

Abstract Class Name: Feature Topology Hierarchy

Superclass - <SEDRIS Abstract Base>

Subclasses

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:

Secondary Pages in DRM Diagram:

Example

See concrete subclasses for examples.

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> instance or a <Model> instance. In general, many different "topological surfaces" may exist within a <Environment Root> instance or a <Model> instance.

Constraints

Component of (two-way)

Inherited Field Elements

This class has no inherited field elements.

Field Elements

SE_Feature_Topology_Level feature_topology_level; 1

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 <Feature Topology Hierarchy> instance.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS