Changes how curvature is calculated at the picked blend curve constraint.

Two tools are available on the Constraint Curvature Type pull-out: Blend constraint geometric curvature, and Blend constraint parametric curvature.

• Parametric curvature

  Align the curvature to an isoparametric direction of the surface.

  This type of curvature is especially useful to achieve curvature continuity with the edge of a surface.

  
• Geometric curvature
  • Construct a plane from the surface normal and the constraint direction (or the normal and the tangent of the curve at the attach point for location constraints).
  • Create a section curve by intersecting this plane with the surface.
  • Align the curvature to this section curve.