Class Name: Areal Feature

Superclass - Primitive Feature

Definition

A Primitive Feature that encloses a bounded region, such as a lake, a forest, or a built-up area.

Primary Page in DRM Diagram:

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Example

1. A lake might be represented as an Areal Feature. It has a Feature Face, which defines its size, shape, and topological relationships; Property Values that describe its characteristics, such as bottom composition, and a Label that identifies it as "Duck Lake".

FAQs

Is Level 3 feature topology required in order for Areal Features to exist?

No. Although in VPF, for example, the mere presence of Faces implies Level 3 topology, this is not the case in SEDRIS. Areal Features may exist at any level of topology.

Can an Areal Feature consist of multiple Feature Faces? Must these Feature Faces be adjacent or connected to one another?

An Areal Feature can consist of multiple Feature Faces. There is no requirement that the Feature Faces be connected to one another. For example, a forest that has a stream and a road passing through it would normally still be represented as a single Areal Feature, but might require multiple Feature Faces.

Constraints

• Image Mapping Functions and Texture Coordinates
• No Attribute Conflicts
• Non Crossing Aggregations
• Non Crossing Associations
• Precedence of Attribute Set Index

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

Composed of (two-way)

• one or more Feature Faces through Face Directions

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

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.