IfcPolyline

Semantic definitions at the entity

Entity definition

The IfcPolyline is a bounded curve with only linear segments defined by a list of Cartesian points. If the first and the last Cartesian point in the list are identical, then the polyline is a closed curve, otherwise it is an open curve.

EXAMPLE Figure 375 illustrates a bounded IfcPolyline and shows the parametric length of each segment and of the total polyline.

Figure 375 — Bounded IfcPolyline with parametric length

NOTE Definition according to ISO/CD 10303-42:1992
A polyline is a bounded curve of n - 1 linear segments, defined by a list of n points, P₁, P₂ ... P_n. The ith segment of the curve is parameterized as follows:
for 1 ≤ i ≤ n - 1
where i - 1 ≤ u ≤ i and with parametric range of 0 <≤ u ≤ n - 1.

NOTE Entity adapted from polyline in ISO 10303-42.

HISTORY New entity in IFC1.0

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
1	Points	IfcCartesianPoint	L[2:?]	The points defining the polyline.	X

Formal Propositions

Rule	Description
SameDim	The space dimensionality of all Points shall be the same.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @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
	StyledByItem	IfcStyledItem @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
IfcGeometricRepresentationItem
IfcCurve
	Dim :=IfcCurveDim(SELF)	IfcDimensionCount		The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.	X
IfcBoundedCurve
IfcPolyline
1	Points	IfcCartesianPoint	L[2:?]	The points defining the polyline.	X

Formal representations

XML Specification

 <xs:element name="IfcPolyline" type="ifc:IfcPolyline" substitutionGroup="ifc:IfcBoundedCurve" nillable="true"/>

 <xs:complexType name="IfcPolyline">

  <xs:complexContent>

   <xs:extension base="ifc:IfcBoundedCurve">

    <xs:sequence>

     <xs:element name="Points">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcCartesianPoint" minOccurs="2" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcCartesianPoint"/>

       <xs:attribute ref="ifc:cType" fixed="list"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcPolyline

 SUBTYPE OF (IfcBoundedCurve);

  Points : LIST [2:?] OF IfcCartesianPoint;

 WHERE

  SameDim : SIZEOF(QUERY(Temp <* Points | Temp.Dim <> Points[1].Dim)) = 0;
END_ENTITY;

 EXPRESS-G diagram

	Polylinie
	Polyline
	Polyligne