Click or drag to resize

SubDEvaluateCurvature Method (SubDComponentParameter, Point3d, Vector3d, Double, Double)

Evaluates the principal curvatures of a point on this SubD's surface.

Namespace:  Rhino.Geometry
Assembly:  RhinoCommon (in RhinoCommon.dll)
Since: 9.0
Syntax
Copy
public bool EvaluateCurvature(
	SubDComponentParameter parameter,
	out Point3d point,
	out Vector3d normal,
	out double kappa1,
	out double kappa2
)

Parameters

parameter
Type: Rhino.GeometrySubDComponentParameter
The parameter to evaluate.
point
Type: Rhino.GeometryPoint3d
The surface point is returned here, or Unset if this fails.
normal
Type: Rhino.GeometryVector3d
The unit surface normal is returned here.
kappa1
Type: SystemDouble
The largest principal curvature, in absolute value, is returned here.
kappa2
Type: SystemDouble
The smallest principal curvature, in absolute value, is returned here.

Return Value

Type: Boolean
True if the evaluation succeeded.
Remarks
This needs second order surface derivatives. They are available throughout the corner quad of an extraordinary vertex, but not exactly on such a vertex: a SubD limit surface is C1 there but generally not C2, so it has no curvature. This returns false in that case, and kappa1 and kappa2 are NaN.
See Also