Class Name: Quad Tree Related Features

Superclass - <Aggregate Feature>

Subclasses

Definition

An instance of this DRM class specifies an aggregation of <Feature Hierarchy> objects in which each component <Feature Hierarchy> represents a branch of a Quad Tree. The quadrant represented by a branch is specified by the <Quad Tree Data> associated with that branch. The bounding region that the <Feature Hierarchy> components occupy is defined by the <Spatial Domain> of the <Quad Tree Related Features>.

Primary Page in DRM Diagram:

• 8

Secondary Pages in DRM Diagram:

Example

1. Consider a region of terrain that is organized into quadrants, where the upper-right quadrant consists of ocean, and the other three quadrants consist of the terrain bordering the ocean. The ocean quadrant is not represented in the producer's system. The region is represented in SEDRIS by a <Quad Tree Related Features> with 3 component <Union Of Features>. (Since the remaining quadrant had no <Features>, it was not represented.)
   
   

   

2. Consider a <Quad Tree Related Features> linked to a <Union Of Features> representing its upper-right quadrant, via a <Quad Tree Data>. The <Quad Tree Data>'s quadrant value is SE_QUADRANT_NORTHEAST.
   
   

   

FAQs

If a <Quad Tree Related Features> has less than 4 components, why is the data being organized under a <Quad Tree Related Features> at all?

A <Quad Tree Related Features> is used when an object in the hierarchy contains spatial components that occupy a certain quadrant. These quadrants might not contain <Primitive Feature> objects, which is why instances of this class can have less than four components.

Where is the <Spatial Domain> component?

<Quad Tree Related Features> automatically has a <Spatial Domain> component, because it is a <Feature>. Unlike <Features> in general, however, <Quad Tree Related Features> has a constraint stating that the <Spatial Domain> component is mandatory.

Constraints

• <<No Attribute Conflicts>>
• <<Non Crossing Aggregations>>
• <<Non Crossing Associations>>
• <<Precedence of Attribute Set Index>>
• <<Non Cyclic Aggregations>>
• <<Colour Mapping Restrictions>>
• <<Image Mapping Functions and Texture Coordinates>>
• <<Distinct Link Objects>>
• <<Quad Tree Related Organizing Principle>>

Associated by (one-way)(inherited)

• zero or one <Hierarchy Summary Item> instance

Associated with (two-way)(inherited)

• zero or more <Feature> instances (notes)
• zero or more <Geometry Hierarchy> instances (notes)
• zero or more <Property Grid> instances (notes)

Composed of (two-way)(inherited)

• zero or more {ordered} <Attribute Set Index> instances
• zero or one <Classification Data> instance
• zero or more <Label> instances
• zero or more <Property Table> instances
• zero or more <Property Table Reference> instances
• zero or more <Property Value> instances
• zero or one <Rendering Priority Level> instance
• zero or one <Reference Surface> instance
• zero or more <Sound Instance> instances
• zero or more <Base Level Of Detail Data> instances
• zero or more <Colour> instances
• zero or more <Feature Topology Hierarchy> instances
• zero or more {ordered} <Image Mapping Function> instances (notes)
• zero or one <Perimeter Data> instance
• zero or one <Presentation Domain> instance (notes)
• zero or more <Property Description> instances
• zero or one <Spatial Domain> instance

Composed of (two-way)

• a bounded set of 1..4 <Feature Hierarchy> instances through <Quad Tree Data>

Composed of (two-way metadata)(inherited)

• zero or one <Access> instance
• zero or more <Browse Media> instances
• zero or more <Cross Reference> instances
• zero or one <Data Quality> instance
• zero or one <Keywords> instance
• zero or one <Point Of Contact> instance
• zero or one <Time Constraints Data> instance

Component of (two-way)(inherited)

• zero or more <Union Of Features> instances
• zero or more <Alternate Hierarchy Related Features> instances through <Hierarchy Data>
• zero or more <Classification Related Features> instances through <Classification Data>
• zero or one <Environment Root> instance
• zero or one <Feature Model> instance
• zero or more <Level Of Detail Related Features> instances through <Base Level Of Detail Data>
• zero or more <Oct Tree Related Features> instances through <Oct Tree Data>
• zero or more <Perimeter Related Features> instances through <Perimeter Data>
• zero or more <Quad Tree Related Features> instances through <Quad Tree Data>
• zero or more <Spatial Index Related Features> instances through <Spatial Index Data>
• zero or more <State Related Features> instances through <State Data>
• zero or more <Time Related Features> instances through <Time Constraints Data>

Inherited Field Elements

Notes

Associated with Notes

Feature

 An association between two <Feature> instances indicates
 that they are alternate representations of the same
 environmental object.

Geometry_Hierarchy

 An association between a <Geometry Hierarchy> instance and a
 <Feature> instance indicates that the <Geometry Hierarchy>
 and the <Feature> are alternate representations of the same
 environmental object.

Property_Grid

 An association between a <Property Grid> instance and a
 <Feature> instance indicates that the <Feature> and the <Property Grid>
 (or some specific cell data within that <Property Grid>) are
 alternate representations of the same environmental object.
 Each associated <Property Grid> will indicate which is the case.

Composed of Notes

Image_Mapping_Function

 This relationship exists to support "attributes for derived objects."
 That is, these components are used only to specify texture mapping
 information for geometry that is to be derived from the
 <Aggregate Feature> by the consumer. These <Image Mapping Function>
 instances shall use <Image Anchor> components to specify the mapping.

Presentation_Domain

 This is needed for cases in which an <Aggregate Feature> is
 significant only for a particular domain, such as radar.

Fields Notes

unique_descendants

 If this value is SE_TRUE, each 'descendant' of this aggregation -
 that is, each <Feature> instance that exists in the component tree
 rooted at the given <Aggregate Feature> - shall be unique, in the
 sense that it shall appear in only one 'branch' of this aggregation.
 If unique_descendants is SE_FALSE, at least one <Feature> instance
 appears in more than one 'branch' of the aggregation.

strict_organizing_principle

 If this value is SE_TRUE, each 'branch' of this aggregation
 strictly complies with the organizing principle for its
 particular subclass. If this value is SE_FALSE, at least
 one 'branch' does not strictly comply with the given
 organizing principle. See the organizing principle constraint
 for each specific subclass for details.