8.20.3.14 IfcPath
8.20.3.14.1 Semantic definition
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). Entity adapted from path defined in ISO 10303-42. New entity in IFC2.0An 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.
Informal Propositions
- A path has dimensionality 1.
- A path is arcwise connected.
- The edges of the path do not intersect except at common vertices.
- A path has a finite, non-zero extent.
8.20.3.14.2 Entity inheritance
8.20.3.14.3 Attributes
| # | Attribute | Type | Description |
|---|---|---|---|
| IfcRepresentationItem (2) | |||
| LayerAssignment | SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems |
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. The inverse attribute LayerAssignments has been added. The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed. |
|
| StyledByItem | SET [0:1] OF IfcStyledItem FOR Item |
Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. The inverse attribute StyledByItem has been added. |
|
| Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes | |||
| IfcPath (1) | |||
| 1 | EdgeList | LIST [1:?] OF UNIQUE IfcOrientedEdge |
The list of oriented edges which are concatenated together to form this path. |
8.20.3.14.4 Formal propositions
| Name | Description |
|---|---|
| IsContinuous |
The end vertex of each edge shall be the same as the start vertex of its successor. |
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8.20.3.14.5 Formal representation
ENTITY IfcPath
SUBTYPE OF (IfcTopologicalRepresentationItem);
EdgeList : LIST [1:?] OF UNIQUE IfcOrientedEdge;
WHERE
IsContinuous : IfcPathHeadToTail(SELF);
END_ENTITY;