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.

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.

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.