DirectedNodePropertyType, directedNode Topological primitives 0-dimensional .1 NodeType, Node

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 141

13.3.3.2 DirectedEdgePropertyType, directedEdge

element name=directedEdge type=gml:DirectedEdgePropertyType complexType name=DirectedEdgePropertyType sequence minOccurs=0 element ref=gml:Edge sequence attribute name=orientation type=gml:SignType default=+ attributeGroup ref=gml:AssociationAttributeGroup attributeGroup ref=gml:OwnershipAttributeGroup complexType A gml:directedEdge property element describes the boundary of topology faces, the coBoundary of topology nodes and is used in the support of topological line features via the gml:TopoCurve expression, see below. The orientation attribute of type gml:SignType expresses the sense in which the included edge is used, i.e. forward or reverse. 13.3.4 Topological primitives 2-dimensional 13.3.4.1 FaceType, Face complexType name=FaceType complexContent extension base=gml:AbstractTopoPrimitiveType sequence element name=isolated type=gml:NodePropertyType minOccurs=0 maxOccurs=unbounded element ref=gml:directedEdge maxOccurs=unbounded element ref=gml:directedTopoSolid minOccurs=0 maxOccurs=2 element ref=gml:surfaceProperty minOccurs=0 sequence attributeGroup ref=gml:AggregationAttributeGroup attribute name=universal type=boolean use=optional default=false extension complexContent complexType element name=Face type=gml:FaceType substitutionGroup=gml:AbstractTopoPrimitive gml:Face represents the 2-dimensional topology primitive and implements ISO 19107 TP_Face see D.2.4.3 and ISO 19107:2003, 7.3.16. The gml:isolated property element implements the role of the same name of the ISO 19107 ―Isolated In‖ association see ISO 19107:2003, 7.3.10.4 and D.2.4.3. The topological boundary of a face gml:directedEdge consists of a sequence of directed edges. If provided, the aggregationType attribute shall have the value ―sequence‖. NOTE 1 All edges associated with the face, including dangling edges, appear in the boundary. A dangling edge has the same face on both sides. Consequently, a dangling edge has two different nodes in its boundary. A dangling edge may share zero, one or two bounding nodes with other edges in the boundary of a face. Two directedEdge elements with opposite orientations reference each dangling edge in the boundary of a face. The non-dangling edges in the boundary of a face comprise one or more topological rings. Each such ring consists of directedEdges connected in a cycle, and is oriented with the face on its left. The optional coboundary of a face gml:directedTopoSolid is a pair of directed solids which are bounded by this face. A positively directed solid corresponds to a solid which lies in the direction of the negatively directed normal to the face in any geometric realization.