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 346 illustrates a bounded IfcPolyline and shows the parametric length of each segment and of the total polyline.

Figure 346 — 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	C
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	C
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.	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.	X
IfcGeometricRepresentationItem
IfcCurve
	Dim :=IfcCurveDim(SELF)	IfcDimensionCount	[1:1]	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

XSD 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