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 = SELFIfcSpiral.Position.Location
• x = SELFIfcSpiral.Position.P[1]
• y = SELFIfcSpiral.Position.P[2]
• A₂ = QuadraticTerm
• A₁ = LinearTerm
• A₀ = ContantTerm

and the second order polynomial spiral is parameterized as: 

where: 

and the parametric range is: -∞ < u < ∞.