#### 8.7.3.14 IfcPolyline

| Polyligne
| Polylinie

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

Figure 142 — 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 ... Pn. 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

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;

Attribute Definitions:

Points | : | The points defining the polyline.

Formal Propositions:

SameDim | : | The space dimensionality of all Points shall be the same.

Inheritance Graph:

ENTITY IfcPolyline

| ENTITY IfcRepresentationItem

| INVERSE

LayerAssignment | : | SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;

| ENTITY IfcGeometricRepresentationItem

| ENTITY IfcCurve

| DERIVE

Dim | : | IfcDimensionCount := IfcCurveDim(SELF);

| ENTITY IfcBoundedCurve

| ENTITY IfcPolyline

Points | : | LIST [2:?] OF IfcCartesianPoint;

END_ENTITY;

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