Class Name: Spatial Index Related Features

Superclass - Aggregate Feature

Definition

An aggregation of Feature Hierarchies in which each component Feature Hierarchy represents a different tile within a spatially indexed (tiled) organization of Primitive Feature objects within a SEDRIS transmittal. The Feature Spatial Index Data link object attached to each component Feature Hierarchy indicates the tile that it represents.

Primary Page in DRM Diagram:

• 8

Example

1. See Spatial Index Related Organizing Principle, example #2.

FAQs

What is the purpose of this class?

This class allows Features to be organized (tiled) according to some spatial index.

My data consists of a collection of Areal Features that are tiled along the lines of a grid, but some Areal Features here and there cross over tile boundaries. Can I organize these Areal Features with a Spatial Index Related Features?

Yes, if its strict_organizing_principle is set to SE_FALSE to indicate that the indexing is not strictly followed (see Spatial Index Related Organizing Principle, example #2). Each tile of the spatial index would be represented by a Feature Hierarchy component of the Spatial Index Related Features.

Where is the origin of the spatial index?

The required Location component of the Spatial Index Related Features specifies the origin of the spatial index, which is its lower-left corner.

Constraints

• Image Mapping Functions and Texture Coordinates
• No Attribute Conflicts
• Non Crossing Aggregations
• Non Crossing Associations
• Precedence of Attribute Set Index
• Non Cyclic Aggregations
• Distinct Link Objects
• Spatial Index Related Organizing Principle

Associated by (one-way)(inherited)

• optionally, a Hierarchy Summary Item

Associated with (two-way)(inherited)

• optionally, some Features
• optionally, some Geometry Hierarchies
• optionally, some Property Grids

Composed of (one-way)(inherited)

• optionally, some {ordered} Attribute Set Indices
• optionally, a Classification Data
• optionally, some Colors
• optionally, some {ordered} Image Mapping Functions (notes)
• optionally, some Labels
• optionally, some Property Tables
• optionally, some Property Table References
• optionally, some Property Values
• optionally, a Rendering Priority Level
• optionally, a Spatial Domain
• optionally, a Reference Surface
• optionally, some Sound Instances
• optionally, some Property Descriptions

Composed of (one-way)

• one Location (notes)

Composed of (two-way)(inherited)

• optionally, some Topology Hierarchies

Composed of (two-way)

• one or more Feature Hierarchies through Feature Spatial Index Data

Composed of (one-way metadata)(inherited)

• optionally, an Access
• optionally, some Browse Graphics
• optionally, some Cross References
• optionally, a Data Quality
• optionally, a Keywords
• optionally, a Point of Contact
• optionally, a Time Constraints Data

Component of (two-way)(inherited)

• optionally, some Union of Features
• optionally, some Alternate Hierarchy Related Features through Feature Hierarchy Data
• optionally, some Classification Related Features through Feature Classification Data
• optionally, an Environment Root
• optionally, a Feature Model
• optionally, some Time Related Features through Feature Time Constraints Data
• optionally, some Level of Detail Related Features through Feature Level of Detail Data
• optionally, some Oct Tree Related Features through Feature Oct Tree Data
• optionally, some Perimeter Related Features through Feature Perimeter Data
• optionally, some Quad Tree Related Features through Feature Quad Tree Data
• optionally, some Spatial Index Related Features through Feature Spatial Index Data
• optionally, some State Related Features through Feature State Data

Inherited Field Elements

Field Elements

Notes

Composed of Notes

Image_Mapping_Function

 Added to support "attributes for derived objects."
 That is, these components are used only to specify
 texture mapping information for geometry that
 is derived from the <Feature> by the consumer.
 These <Image Mapping Functions> must use
 <Image Anchor> components to specify the mapping.

Location

 The origin of the collection.  The lower-left corner.

Fields Notes

unique_descendants

 If true, then for any object that exists 'below' this aggregation,
 each object will appear in only one 'branch' of this aggregation.
 If false, then objects may appear in multiple 'branches' of this
 aggregation.

independent_topologies

 If true, then each 'branch' from this aggregation is its own,
 independent topology.  If false, then all of the branches exist
 within the same topology.

strict_organizing_principle

 If true, then each 'branch' strictly follows the rules of this
 aggregation.  If false, then each 'branch' might bend the rules a bit.
 For example, if this is a spatial aggregation, than a value of true
 indicates that objects will *not* cross the spatial extents defined
 by this aggregation relationship, and a value of false indicates
 that objects might cross those bounds.  For another example, if this
 is a time-based aggregation, then a value of true indicates that all
 branches will only contain data valid for the times specified for
 each branch, and a value of false indicates that the branches have
 the option of including data that falls outside of the specified
 time ranges for that branch.

sparse

 If SE_FALSE, then all column and row entries (all expected Feature
 Hierarchy components) are present.  If SE_TRUE, one or more entries
 are not present.

column_width

 length of a cell in the given units along the X axis

row_width

 length of a cell in the given units along the Y axis