The SEDRIS Data Representation Model
APPENDIX A - Classes
Property Grid Hook Point

Class Name: Property Grid Hook Point

Superclass - <Geometry Hierarchy>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is used to "instance" a <Property Grid> into the spatial scope of an <Environment Root> or <Model>. In particular, the origin of the spatial axes of a component <Property Grid> is located at the <Property Grid Hook Point>'s component <Location>.

Since a <Property Grid Hook Point> separates a <Property Grid>'s cell data from the <Location> of its origin, <Property Grid> instances can be shared by several <Property Grid Hook Point> instances.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a 1-dimensional <Property Grid> classified as ECC_WATER_BODY_BATHYMETRY_PROPERTY_SET that contains a depth axis only. The <Property Grid Hook Point> <Location> serves to position this grid into the currently scoped 'world' spatial reference frame.

  2. Consider a 2-dimensional <Property Grid> instance classified as ECC_TERRAIN_ELEVATION that contains elevation relative to the south-west corner of the grid. The <Property Grid Hook Point> instance's <Location> component serves to position this grid corner into the currently scoped 'world' spatial reference frame.

  3. A <Property Grid Hook Point> instance connecting a <Property Grid> instance of terrain elevation data from DTED to the geometry of an <Environment Root> instance.

FAQs

If a <Property Grid> has all 3 spatial axes, isn't the hook <Location> redundant?

No, the hook point <Location> serves several purposes.

  1. Since the spatial axes are relative, the hook <Location> provides the axis offset origins.

  2. It makes a <Location> associated with the grid visible to API search filters (in the currently scoped 'world' spatial reference frame).

Constraints

Associated to (one-way) (inherited)

Associated by (one-way) (inherited)

Associated with (two-way)

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

Geometry_Hierarchy

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

Associated from Notes


Feature_Representation

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

Geometry_Hierarchy

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

Hierarchy_Summary_Item

 An association from a <Hierarchy Summary Item> instance to a
 <Geometry Hierarchy> indicates that the <Hierarchy Summary Item>
 summarizes that <Geometry Hierarchy>.

Reference_Surface

 An association from a <Reference Surface> instance to a
 <Geometry Hierarchy> indicates that the <Geometry Hierarchy>
 organizes the geometric objects that specify the resolution
 surface of the <Reference Surface>.

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Last updated: July 16, 2004 Copyright © 2004 SEDRIS