The SEDRIS Data Representation Model
APPENDIX A - Classes
Feature Model Instance

Class Name: Feature Model Instance

Superclass - <Feature Hierarchy>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies a single use of a <Feature Model> instance within a given transmittal, including variations or specialization unique to that case. In particular, a <Feature Model Instance> instance is used to transform a <Feature Model> instance into the SRF of another <Feature Model> instance or that of an <Environment Root> instance.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a <Model> instance representing a forested area, consisting of a <Geometry Model> component describing its renderable geometry and a <Feature Model> component describing it in terms of a collection of <Areal Feature> instances. The <Geometry Hierarchy> component of the <Geometry Model> component and the <Union Of Features> component of the <Feature Model> component are connected by association relationships to indicate that they are alternate representations of the same entity.

    Wherever the <Model> instance is to be instantiated, a <Feature Model Instance> instance is placed, with the appropriate <Transformation> component to locate it in space and any <Expression> instances required for <Variable> instances within the <Feature Model> instance.

FAQs

Where can users find further information on feature topology in the DRM?

See P4V4 of the SEDRIS Documentation Set for further information.

Constraints

Associated to (one-way) (inherited)

Associated to (one-way)

Associated by (one-way) (inherited)

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

This class has no inherited field elements.

Notes

Associated to Notes


Feature_Representation

An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Property_Grid

An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> link object on the association relationship. Each associated <Property Grid> instance indicates whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.

Associated from Notes


Feature_Representation

An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Property_Grid

An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> link object on the association relationship. Each associated <Property Grid> instance indicates whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.

Composed of Notes


Transformation

The <Transformation> component positions and orients the <Feature Model Instance> instance in the target SRF.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS