The SEDRIS Data Representation Model
APPENDIX A - Classes Feature Face |
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An instance of this DRM class is a 2-dimensional <Feature Topology> instance used to represent the region that corresponds to an <Areal Feature>, bounded by one or more <Feature Edge> instances.
An <Areal Feature> representing a forest would be defined by one or more <Feature Edge> instances. At feature topology level 4, the walls of a building might be defined by a collection of <Feature Face> instances.
<Feature Face> instances are required whenever there are <Areal Feature> instances, regardless of the feature topology level.
Yes; see this class' constraints.
Yes. <Feature Face> instances may exist at any feature topology level in order to define the extents of <Areal Feature> instances. See this class' constraints for further details.
These associations exist to support cross-tile topology. In SEDRIS terms, this is topology that appears in more than one branch of a <Spatial Index Related> or <Perimeter Related> aggregation, namely, in a <Spatial Index Related Features>, <Spatial Index Related Feature Topology>, <Perimeter Related Features>, or <Perimeter Related Feature Topology>).
<Feature Node>, <Feature Edge>, and, in 3D, <Feature Face> instances can be located on the boundary of a tile. When this happens, they have "counterparts" in each of the adjacent tiles that share the boundary. These associations allow <Feature Node>, <Feature Edge>, and <Feature Face> instances to identify their counterparts, if any.
In 2D,
However, the multiplicity in the DRM is there to support 3D tiles
(e.g., a regular set of rectangular blocks of space).
In 3D,
These <Feature Edge> instances are those that border the given <Feature Face> instance. The converse of this relationship is that between <Feature Face Ring> and <Feature Edge>.
If specified, these <Feature Node> instances are contained within the <Feature Face>; see this class' constraints for further details.
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