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 1 illustrates a bounded IfcPolyline and shows the parametric length of each segment and of the total polyline.
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, P~1~, P~2~ ... P~n~. The _i_th 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
|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.|
> 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.
|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.|
> IFC2x3 CHANGE The inverse attribute StyledByItem has been added.
|Dim||INVALID||The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.|
|1||Points||LIST [2:?] OF IfcCartesianPoint||The points defining the polyline.|
ENTITY IfcPolyline SUBTYPE OF (IfcBoundedCurve); Points : LIST [2:?] OF IfcCartesianPoint; WHERE SameDim : SIZEOF(QUERY(Temp <* Points | Temp.Dim <> Points.Dim)) = 0; END_ENTITY;