IFC 4.3.x development IfcPolyline

Change log


deletionswhere_rulesWR41 Semantic definitions at the entity

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.

"polyline examples"

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:

Image    for 1 ≤ in - 1 where i - 1 ≤ ui and with parametric range of 0 <≤ un - 1.

NOTE  Entity adapted from polyline in ISO 10303-42.

HISTORY  New entity in IFC1.0 Attributes

# Attribute Type Description
LayerAssignmentSET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItemsAssignment 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 inheritance

dot_inheritance IfcPolyline IfcPolyline IfcBoundedCurve IfcBoundedCurve IfcPolyline->IfcBoundedCurve IfcBoundedCurve_children 4 more... IfcBoundedCurve_children->IfcBoundedCurve IfcCurve IfcCurve IfcBoundedCurve->IfcCurve IfcCurve_children 7 more... IfcCurve_children->IfcCurve IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcCurve->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem Formal representations

ENTITY IfcPolyline
 SUBTYPE OF (IfcBoundedCurve);
	Points : LIST [2:?] OF IfcCartesianPoint;
	SameDim : SIZEOF(QUERY(Temp <* Points | Temp.Dim <> Points[1].Dim)) = 0;