IfcPolyline

BACnet MVD

#### IfcPolyline

Natural language names

| Polylinie
| Polyline
| Polyligne

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

Figure 321 — 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

Attribute definitions

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

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 | X
IfcBoundedCurve
IfcPolyline
1 | Points | IfcCartesianPoint | L[2:?] | The points defining the polyline. | X | 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

`

Link to this page