DefinitionAn object is a <CANONICALLY PARAMETERISED SURFACE CURVE SWEPT SURFACE>if and only if: it is a <SURFACE CURVE SWEPT SURFACE>; it is a <PARAMETERISED SURFACE>; it has the canonical parameterisation defined by a directrix and reference surface as follows: σ(u,v) = μ(u) + T0,u(λ(v)) as defined in ISO 15926 Part 3 Section 4.6.3.14