A clothoid is a planar curve in the form of a spiral. This curve has the property that the curvature varies linearly with the arc length.
NOTE Definition according to ISO 10303-42:2003
Interpretation of the data shall be as follows:
and the parametric range is: -∞ < u < ∞
The arc length s of the curve, from the point C, is given by the formula:
The curvature κ and radius of the curvature ρ, at any point of the curve, are related to the arc length s by the formulae:
NOTE Formulae adapted from clothoid defined in ISO 10303-42
|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.|
|2||ClothoidConstant||IfcLengthMeasure||The constant which defines the relationship between curvature and arc length for the curve.|
ENTITY IfcClothoid SUBTYPE OF (IfcSpiral); ClothoidConstant : IfcLengthMeasure; END_ENTITY;