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The SEDRIS Data Representation Model
APPENDIX A - Classes Volumetric Feature |
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An instance of this DRM class is a <Primitive Feature> that encloses a bounded region of three-dimensional space, such as a building or a room within a building.
Consider a <Volumetric Feature> instance representing a building. It has an associated <Feature Volume> instance, which defines its extent, shape, and topological relationships; a <Classification Data> component that classifies it as an ECC_BUILDING; <Property Value> components that describe its characteristics, such as material composition, and a <Label> instance that identifies it as "The Empire State Building".
No. In order for <Volumetric Feature> instances to exist, the SRF must be three-dimensional, and at least one <Feature Volume> object must exist.
A <Volumetric Feature> can consist of multiple <Feature Volume> instances. There is no requirement that these <Feature Volume> instances be adjacent or connected to one another. For example, a house with a detached garage could be represented as a single <Volumetric Feature> with two associated <Feature Volume> instances (one for the house itself, and one for the garage).
An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> instance on the association relationship.
An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> instance on the association relationship.
An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> instance on the association relationship. Each associated <Property Grid> instance will indicate whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.
An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> instance on the association relationship.
An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> instance on the association relationship.
An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> instance on the association relationship. Each associated <Property Grid> instance will indicate whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.
These components support *attributes for derived objects*; that is, they are used only to specify texture mapping information for geometry that is derived from the <Primitive Feature> by the consumer. These <Image Mapping Function> components shall use <Image Anchor> components to specify the mapping.
This is needed because in many cases, a <Primitive Feature> may be significant only for a particular domain, such as radar.
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