The SEDRIS Data Representation Model
APPENDIX A - Classes
Point Feature

Class Name: Point Feature

Superclass - <Primitive Feature>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies a <Primitive Feature> instance for which the spatial information needed for the representation can be abstracted to a single topologically significant location. This is sometimes referred to as a zero-dimensional location, since the topology associated with a <Point Feature> instance does not provide length, width, or height information.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a well represented by a <Point Feature> instance. The <Point Feature> instance has a <Classification Data> component classifying it as ECC_WELL, an associated <Feature Node> instance specifying its location, and <Property Value> components specifying its depth below the terrain surface and the potability of the water it contains.

  2. Consider a road interchange represented as a <Point Feature> instance. The <Point Feature> instance has a <Classification Data> component classifying it as ECC_ROAD_INTERCHANGE, and an associated <Feature Node> instance specifying its location. In addition, the <Feature Node> instance in this example is associated with some <Feature Edge> instances that are part of the topology of some <Linear Feature> instances representing the roads in question.

  3. Consider a small building represented as a <Point Feature> instance. The <Point Feature> instance has a <Feature Node> instance specifying its location, a <Classification Data> component classifying it as ECC_BUILDING, and a set of <Property Value> components that describe its characteristics, such as its EAC_HEIGHT and its EAC_BUILDING_FUNCTION.

FAQs

Can a <Point Feature> instance's topology consist of multiple <Feature Node> instances?

No. A <Point Feature> instance's topology shall consist of only a single <Feature Node> instance.

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.

Associated with Notes


Feature_Node

The <Feature Node> instance associated with a <Point Feature> instance represents the topology of that <Point Feature> instance.

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