Class Name: State Related Features

Superclass - Aggregate Feature

Definition

An aggregation of Feature Hierarchies that are differentiated by the field values of the Feature State Data link objects attached to the aggregations used to reach the Feature Hierarchy objects. State Related Features is used to group discrete changes in Features. State provides a mechanism to select discrete states from a possibly continuous state value.

Primary Page in DRM Diagram:

• 8

Example

1. Consider a Feature Model describing a road in various states of damage, e.g. after flooding. The road's topological connections are different in various states of damage, due to bridges being washed away and various road segments being blocked due to fallen trees and the like.

   Consequently, the Feature Model consists of a State Related Features object, with state_tag = EDCS_AC_DAMAGE_GENERAL and active_state = 0.0 % (since we will initially start with an undamaged road, before flooding).

                 <State Related Features>
                           <>
                           |
             ---------------------------------
             |                               |
             |--<Feature State Data>         |--<Feature State Data>
             |     0 % - 20 %                |    20% - 50 %
             |                               |
         <Union of Features>            <Union of Features>
   

   The Feature State Data for each branch indicates the range of percent damage for which that branch describes the road's feature topology.

FAQs

Is State Related Features the only way to represent multi-state objects in SEDRIS?

No. Control Links can be used to provide a fine level of control over state by changing fields instead of representing states as different Features.

Constraints

• Image Mapping Functions and Texture Coordinates
• No Attribute Conflicts
• Non Crossing Aggregations
• Non Crossing Associations
• Precedence of Attribute Set Index
• Non Cyclic Aggregations
• Active State Value
• Distinct Link Objects
• Non Overlapping State Data

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 (two-way)(inherited)

• optionally, some Topology Hierarchies

Composed of (two-way)

• one or more Feature Hierarchies through Feature State Data
• optionally, a Feature State Control Link

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.

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.

state_tag

 The state by which the component <Feature Hierarchies> are being
 differentiated; must be an EDCS State Code (ESC).

 Refer to the list of ESCs to understand their meanings, as well
 as the allowable ranges or enumerated values. (Note that the
 list of ESCs is a subset of the list of EDCS Attribute Codes
 (EACs), which is why a EDCS_AC_ID is used to identify the state.)

active_state_value

 The default state.

 If a <Feature State Control Link> is present, then this field
 is its target.