188.8.131.52.1 Semantic definition
The IfcSecondOrderPolynomialSpiral is a specialization of IfcSpiral. The curvature κ and radius of the curvature ρ, at any point of the curve, are related to the arc length s by the second order formulae:
Interpretation of the parameters:
C = SELF\IfcSpiral.Position.Location x = SELF\IfcSpiral.Position.P y = SELF\IfcSpiral.Position.P A2 = QuadraticTerm A1 = LinearTerm A0 = ContantTerm
and the second order polynomial spiral is parameterized as:
and the parametric range is: -∞ < u < ∞.
184.108.40.206.2 Entity inheritance
|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.
|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.
This attribute is formally derived.
The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.
No description available.
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The constant that defines the quadratic term in the equation which defines the relation between curvature and arc length for the curve.
The constant that defines the linear term in the equation which defines the relation between curvature and arc length for the curve.
The constant that defines the constant term in the equation which defines the relation between curvature and arc length for the curve.
220.127.116.11.4 Formal representation
ENTITY IfcSecondOrderPolynomialSpiral SUBTYPE OF (IfcSpiral); QuadraticTerm : IfcLengthMeasure; LinearTerm : OPTIONAL IfcLengthMeasure; ConstantTerm : OPTIONAL IfcLengthMeasure; END_ENTITY;