The SEDRIS Data Representation Model
APPENDIX A - Classes
Linear Feature

Class Name: Linear Feature

Superclass - <Primitive Feature>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is a <Primitive Feature> instance with a one-dimensional structure such as a road, a stream, or a power line.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a <Linear Feature> instance representing a road as depicted in Figure 6.27:

    Linear Feature, Example 1

    Figure 27 — <DRM Linear Feature> example

    This <Linear Feature> instance has an ordered set of <Feature Edge> instances defining the 2D or 3D path of its centreline. The <Classification Data> component identifies it as a road, while the <Property Value> instances describe the characteristics of the road.

    NOTE  Individual segments of the road with different surface characteristics can each be attributed with their own <Property Value> components.

FAQs

Can a <Linear Feature> instance consist of multiple <Feature Edge> instances?

Yes. However, these <Feature Edge> instances shall form an ordered sequence, such that each consecutive pair of <Feature Edge> instances share a common <Feature Node>. Also, any properties of the feature shall remain the same throughout its length. For example, a single road feature (Interstate 95) could conceivably consist of a linear sequence of hundreds or thousands of <Feature Edge> instances.

Constraints

Associated to (one-way) (inherited)

Associated by (one-way) (inherited)

Associated with (two-way)

Composed of (two-way) (inherited)

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


Image_Mapping_Function

These components support attributes for derived objects; that is, they are used only to specify texture mapping information for geometry that is derived from the <Primitive Feature> instance by the consumer. These <Image Mapping Function> components shall use <Image Anchor> components to specify the mapping.


Presentation_Domain

The <Presentation Domain> component is needed because, in many cases, a <Primitive Feature> instance may be significant only for a particular domain, such as radar.

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Last updated: July 26, 2006 Copyright © 2006 SEDRIS™