IfcPath

Natural language names
Pfad - Topologie
Path
Chemin
Semantic definitions at the entity
Entity definition

NOTE  Definition according to ISO/CD 10303-42:1992
A path is a topological entity consisting of an ordered collection of oriented edges, such that the edge start vertex of each edge coincides with the edge end of its predecessor. The path is ordered from the edge start of the first oriented edge to the edge end of the last edge. The BOOLEAN value sense in the oriented edge indicates whether the edge direction agrees with the direction of the path (TRUE) or is the opposite direction (FALSE).

An individual edge can only be referenced once by an individual path. An edge can be referenced by multiple paths. An edge can exist independently of a path.

NOTE  Entity adapted from path defined in ISO 10303-42.

HISTORY  New entity in IFC2.0

Informal Propositions:

  1. A path has dimensionality 1.
  2. A path is arcwise connected.
  3. The edges of the path do not intersect except at common vertices.
  4. A path has a finite, non-zero extent.
Attribute definitions
#AttributeTypeCardinalityDescription G
1EdgeListIfcOrientedEdgeL[1:?] The list of oriented edges which are concatenated together to form this path. X
Formal Propositions
RuleDescription
IsContinuousThe end vertex of each edge shall be the same as the start vertex of its successor.
Inherited definitions from supertypes
Entity inheritance IfcTopologicalRepresentationItem IfcRepresentationItem
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRepresentationItem
LayerAssignmentIfcPresentationLayerAssignment
@AssignedItems
S[0:1]Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.
IFC2x3 CHANGE  The inverse attribute LayerAssignments has been added.
IFC4 CHANGE  The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
X
StyledByItemIfcStyledItem
@Item
S[0:1]Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.
IFC2x3 CHANGE  The inverse attribute StyledByItem has been added.
X
IfcTopologicalRepresentationItem
IfcPath
1EdgeListIfcOrientedEdgeL[1:?] The list of oriented edges which are concatenated together to form this path. X
Formal representations
XML Specification
 <xs:element name="IfcPath" type="ifc:IfcPath" substitutionGroup="ifc:IfcTopologicalRepresentationItem" nillable="true"/>
 <xs:complexType name="IfcPath">
  <xs:complexContent>
   <xs:extension base="ifc:IfcTopologicalRepresentationItem">
    <xs:sequence>
     <xs:element name="EdgeList">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcOrientedEdge" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcOrientedEdge"/>
       <xs:attribute ref="ifc:cType" fixed="list-unique"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcPath
 SUBTYPE OF (IfcTopologicalRepresentationItem);
  EdgeList : LIST [1:?] OF UNIQUE IfcOrientedEdge;
 WHERE
  IsContinuous : IfcPathHeadToTail(SELF);
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Link to this page  Link to this page