Table 6

Table 6.153—DRM_Level_Of_Detail_Related_Geometry

Property

Description

Superclass

· <DRM Aggregate Geometry>

Class

· <DRM Level Of Detail Related Geometry>

Subclass

· none

Definition

An object of this DRM class specifies an aggregation of <DRM Geometry Hierarchy>s in which each component <DRM Geometry Hierarchy> is an alternate representation of the same entity at a different level of detail. Each component <DRM Geometry Hierarchy> is a collection of <DRM Geometry>s with a different, possibly overlapping, value, representing alternatives that should be used at different viewing properties such as ranges, map scales, and spatial resolution.

Example(s)

· Consider a <DRM 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 two distance-related levels of detail: 0-500 meters, and 500-100 meters. Level of Detail Related Geometry, Example 1

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

Inherited field elements

field_name	range	Field_Data_Type
unique_descendants¹		Boolean
strict_organizing_principle²		Boolean

Field elements

field_name	range	Field_Data_Type
lod_data_type		LOD_Data_Type

Associated to (one-way) (inherited)

· none

Associated to (one-way)

· none

Associated by (one-way) (inherited)

· zero or one <DRM Hierarchy Summary Item>

· zero or more <DRM Reference Surface>s

Associated by (one-way)

· none

Associated with (two-way) (inherited)

· zero or more <DRM Feature>

· zero or more <DRM Geometry Hierarchy>s

Associated with (two-way)

· none

Composed of (two-way) (inherited)

· zero or more {ordered} <DRM Attribute Set Index>s

· zero or more <DRM Base Level Of Detail Data>s

· zero or one <DRM Bounding Volume>

· zero or one <DRM Centre Of Buoyancy>

· zero or one <DRM Centre Of Mass>

· zero or one <DRM Centre Of Pressure>

· zero or one <DRM Classification Data>

· zero or more <DRM Collision Volume>s

· zero or more {ordered} <DRM Colour>

· zero or one <DRM Conformal Behaviour>⁴

· zero or more <DRM Geometry Topology Hierarchy>s

· zero or more <DRM Hierarchical Table>s

· zero or more {ordered} <DRM Image Mapping Function>s

· zero or one <DRM Light Rendering Properties>

· zero or more <DRM Light Source>s

· zero or one <DRM LSR Transformation>

· zero or one <DRM Overload Priority Index>

· zero or one <DRM Perimeter Data>

· zero or one <DRM Point Of Contact>

· zero or one <DRM Presentation Domain>

· zero or more <DRM Property Description>s

· zero or more <DRM Property Table>s

· zero or more <DRM Property Table Reference>s

· zero or more <DRM Property Value>s

· zero or one <DRM Reference Surface>

· zero or one <DRM Rendering Priority Level>

· zero or one <DRM Rendering Properties>

· zero or more <DRM Sound Instance>

· zero or one <DRM Spatial Domain>

· zero or one <DRM Stamp Behaviour>⁵

· zero or one <DRM Time Constraints Data>

Composed of (two-way)

· one or more <DRM Geometry Hierarchy>s through <DRM Base Level Of Detail Data>

Composed of (two-way metadata) (inherited)

· zero or one <DRM Access>

· zero or more <DRM Browse Media>s

· zero or one <DRM Citation>

· zero or more <DRM Cross Reference>s

· zero or one <DRM Data Quality>

· zero or one <DRM Description>

· zero or one <DRM Keywords>

· zero or one <DRM Point Of Contact>

Composed of (two-way metadata)

· none

Component of (two-way) (inherited)

· zero or more <DRM Alternate Hierarchy Related Geometry>s through <DRM Hierarchy Data>s

· zero or more <DRM Animation Related Geometry>s

· zero or more <DRM Classification Related Geometry>s through <DRM Classification Data>s

· zero or one <DRM Environment Root>

· zero or one <DRM Geometry Model>

· zero or more <DRM Level Of Detail Related Geometry>s through <DRM Base Level Of Detail Data>s

· zero or more <DRM Oct Tree Related Geometry>s through <DRM Oct Tree Data>s

· zero or more <DRM Perimeter Related Geometry>s through <DRM Perimeter Data>s

· zero or more <DRM Quad Tree Related Geometry>s through <DRM Quad Tree Data>s

· zero or more <DRM Separating Plane Relations>s through <DRM Separating Plane Data>s

· zero or more <DRM Spatial Index Related Geometry>s through <DRM Spatial Index Data>s

· zero or more <DRM State Related Geometry>s through <DRM State Data>s

· zero or more <DRM Time Related Geometry>s through <DRM Time Constraints Data>s

· zero or more <DRM Union Of Geometry Hierarchy>s

Component of (two-way)

· none

Constraints

· Colour mapping restrictions

· Distinct link objects

· Image mapping functions and texture coordinates

· Level of detail related organizing principle

· No attribute conflicts

· Non-crossing aggregations

· Non-crossing associations

· Non-cyclic aggregations

· Precedence of Attribute_Set_Index

Notes

¹ If TRUE, for any object that exists 'below' this aggregation, each object will appear in only one 'branch' of this aggregation. If FALSE, objects may appear in multiple 'branches' of this aggregation.

² If TRUE, each 'branch' strictly follows the rules of this aggregation. If FALSE, each 'branch' might bend the rules a bit. For example, if this is a spatial aggregation, 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, 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.

Class diagram