The SEDRIS Data Representation Model
APPENDIX A - Classes
Feature Volume Shell

Class Name: Feature Volume Shell

Superclass - <SEDRIS Abstract Base>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies the one-directional topological relationship from a <Feature Volume> instance to the collection of two or more <Feature Face> instances that define one of its boundaries (external or internal).

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

  1. Consider a <Volumetric Feature> instance V representing a building. V has:

    1. an associated <Feature Volume> instance that defines its extent, shape, and topological relationships;
    2. a <Classification Data> component that classifies it as an ECC_BUILDING;
    3. <Property Value> components that describe its characteristics, such as material composition; and
    4. a <Label> component that identifies it as "The Empire State Building".

    The external boundary of the <Feature Volume> instance consists of a single <Feature Volume Shell> instance that is associated with the <Feature Face> instances representing the walls, roof, and (basement) floor of the building.

FAQs

When are <Feature Volume Shell> instances required?

All <Feature Volume> instances except the instance representing the universal volume are required to have at least one <Feature Volume Shell> component, representing its external boundary. All <Feature Volume> instances, including the instance representing the universal volume, may also have any number of <Feature Volume Shell> components that define internal boundaries (that is, "holes") within the <Feature Volume>.

Can the same <Feature Face> appear more than once in the collection of <Feature Face> instances making up a <Feature Volume Shell>?

Yes. A <Feature Face> can appear up to twice in a <Feature Volume Shell>, once with each orientation.

Constraints

Associated to (one-way)

Component of (two-way)

Inherited Field Elements

This class has no inherited field elements.
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Last updated: July 26, 2006 Copyright © 2006 SEDRIS™