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The SEDRIS Data Representation Model
APPENDIX A - Classes Geometry Model |
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An instance of this DRM class specifies a reusable representation of the geometry aspects of an environmental object represented by its <Model> aggregate.
The <Geometry Model> instance represents the hull of a tank.
Consider a <Model> instance M, specified in an LSR 3D SRF, representing a missile and specifying a geometric representation. M is a component of a <Model Library> instance containing many <Model> instances representing missiles, each of which for consistency is expected to be specified in the same LSR 3D SRF and oriented pointing down the positive V axis.
In the case of M, however, the <Geometry Model> component was provided by a data provider who uses the desired LSR 3D SRF, but for whom it is customary to specify missiles pointing down the -W axis. To make M consistent with the rest of the <Model Library> instance in which it resides, the <Geometry Model> component of M has an <LSR Transformation> component to reorient it to point down the positive V axis.
A <Geometry Model> instance may be as large and complex as a large terrain model, or as simple as a single polygon at the lowest level of detail for some environmental object.
The <Geometry Model> class has a formal <LSR Transformation> component to allow all <Model> components of a <Model Library> instance to be given a uniform orientation. (Note that a data provider is not required to give them all a uniform orientation.)
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