Class Name: Level of Detail Related Geometry

Superclass - Aggregate Geometry

Definition

An aggregation of Geometry Hierarchies in which each component Geometry Hierarchy is an alternate representation of the same entity at a different level of detail. Each component Geometry Hierarchy is a collection of Geometries with a different, possibly overlapping, Geometry Level of Detail Data value, representing alternatives that should be used at different viewing ranges, map scales, spatial resolution, etc.

Primary Page in DRM Diagram:

• 4

Example

1. Consider a Model of a house, organized based on viewing ranges. If the viewer is farther away than 1000 meters, the house is not visible. From 500 meters to 1000 meters, the roof and walls are visible but not in great detail. From 0 meters to 500 meters, the windows and door become visible. Consequently, the Model is visible at 2 distance-related levels of detail: 0-500 meters, and 500-100 meters.
   

   For the more detailed 0.0 - 500.0 meters, different "wall" Models are instanced for the walls containing the windows and doors; otherwise, the structure of the two levels, for this example, is similar.

FAQs

Constraints

• No Attribute Conflicts
• Non Crossing Aggregations
• Non Cyclic Aggregations
• Precedence of Attribute Set Index
• Non Crossing Associations
• Color Mapping Restrictions
• Image Mapping Functions and Texture Coordinates
• Distinct Link Objects

Associated by (one-way)(inherited)

• optionally, a Hierarchy Summary Item
• optionally, some Reference Surfaces

Associated with (two-way)(inherited)

• optionally, some Features
• optionally, some Geometry Hierarchies

Composed of (one-way)(inherited)

• optionally, some {ordered} Attribute Set Indices
• optionally, a Classification Data
• optionally, some Property Tables
• optionally, some Property Table References
• optionally, some Property Values
• optionally, a Reference Surface
• optionally, some Sound Instances
• optionally, a Spatial Domain
• optionally, a Bounding Volume
• optionally, a Center of Buoyancy
• optionally, a Center of Mass
• optionally, a Center of Pressure
• optionally, some Collision Volumes
• optionally, a Conformal Behavior
• optionally, a LSR Transformation
• optionally, an Overload Priority Index
• optionally, some Property Descriptions
• optionally, a Stamp Behavior
• optionally, some {ordered} Colors
• optionally, a Light Rendering Properties
• optionally, a Rendering Properties
• optionally, some {ordered} Image Mapping Functions
• optionally, a Rendering Priority Level

Composed of (two-way)(inherited)

• optionally, some Hierarchical Tables
• optionally, some Light Sources

Composed of (two-way)

• one or more Geometry Hierarchies through Geometry Level of Detail Data

Composed of (one-way metadata)(inherited)

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

Component of (two-way)(inherited)

• optionally, some Alternate Hierarchy Related Geometries through Geometry Hierarchy Data
• optionally, some Animation Related Geometries
• optionally, some Classification Related Geometries through Geometry Classification Data
• optionally, an Environment Root
• optionally, some Geometry Separating Plane Relations through Geometry Separating Plane Data
• optionally, a Geometry Model
• optionally, some Level of Detail Related Geometries through Geometry Level of Detail Data
• optionally, some Oct Tree Related Geometries through Geometry Oct Tree Data
• optionally, some Time Related Geometries through Geometry Time Constraints Data
• optionally, some Perimeter Related Geometries through Geometry Perimeter Data
• optionally, some Quad Tree Related Geometries through Geometry Quad Tree Data
• optionally, some Spatial Index Related Geometries through Geometry Spatial Index Data
• optionally, some State Related Geometries through Geometry State Data
• optionally, some Union of Geometry Hierarchies

Inherited Field Elements

Field Elements

Notes

Fields Notes

unique_descendants

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

independent_topologies

 If SE_TRUE, then each 'branch' from this aggregation is its own,
 independent topology.  If SE_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.