The SEDRIS Data Representation Model
APPENDIX A - Classes
Geometry Model Instance

Class Name: Geometry Model Instance

Superclass - <Geometry Hierarchy>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies a single use of a <Geometry Model> instance within a given transmittal, including variations or specialization unique to that case. In particular, a <Geometry Model Instance> instance is used to transform a <Geometry Model> instance into the SRF of another <Geometry Model> instance or that of an <Environment Root> instance.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a <Model> instance representing a building consisting of a <Geometry Model> component describing its geometric representation, where the <Model> instance is specified in an LSR 3D SRF.

    To instantiate this <Model> instance in an <Environment Root> instance which specifies a Celestiodetic 3D SRF, the data provider constructs a <Geometry Model Instance> instance with a <World Transformation> component, and incorporates it into the <Geometry Hierarchy> component of that <Environment Root> instance. The <World Transformation> instance specifies the <CD 3D Location> instance to which the origin of the <Model> instance is mapped, together with any other transformation information required to orient and scale the <Model> instance properly.

  2. Consider a <Geometry Model> instance R describing the rotor of a helicopter, and intended for use within a larger <Geometry Model> instance of the entire helicopter. Both are specified in 3D LSR SRFs.

    The helicopter model contains a <Geometry Model Instance> instance of R, with an <LSR Transformation> component L containing a <Rotation> instance with a <Rotation Control Link> component. L specifies both the transformation required to position the rotor within the helicopter model, and the <Variable> instance within the larger helicopter <Model> instance that is plugged into the internal <Variable> instance of R for angle of rotation.

FAQs

No FAQs supplied.

Constraints

Associated to (one-way) (inherited)

Associated to (one-way)

Associated by (one-way) (inherited)

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

This class has no inherited field elements.

Notes

Associated to Notes


Feature_Representation

An association between a <Feature Representation> instance and a <Geometry Hierarchy> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between two <Geometry Hierarchy> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Model

An association from a <Geometry Model Instance> instance to a <Geometry Model> instance indicates that the <Geometry Model Instance> instances that particular <Geometry Model> instance.

Associated from Notes


Feature_Representation

An association between a <Feature Representation> instance and a <Geometry Hierarchy> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between two <Geometry Hierarchy> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Hierarchy_Summary_Item

An association from a <Hierarchy Summary Item> instance to a <Geometry Hierarchy> instance indicates that the <Hierarchy Summary Item> instance summarizes that <Geometry Hierarchy> instance.


Reference_Surface

An association from a <Reference Surface> instance to a <Geometry Hierarchy> instance indicates that the <Geometry Hierarchy> instance organizes the geometric objects that specify the reference surface geometry of the <Reference Surface> instance.

Composed of Notes


Conformal_Behaviour

The <Conformal Behaviour> components allow a <Geometry Model Instance> instance to conform to the underlying geometry. If present, the <Conformal Behaviour> components are applied after any <Transformation> instance that is present.


Transformation

The <Transformation> component positions and orients the <Geometry Model Instance> instance in the target SRF.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS