ComputeDerivatives Method

Returns the first partial derivatives of the underlying surface at the specified point.

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: (17.0.484.0)


public Transform ComputeDerivatives(
	UV point
Visual Basic
Public Function ComputeDerivatives ( _
	point As UV _
) As Transform
Visual C++
Transform^ ComputeDerivatives(
	UV^ point


Type: Autodesk.Revit.DB UV
The parameters to be evaluated, in natural parameterization of the face.

Return Value

A transformation containing tangent vectors and a normal vector.


The following is the meaning of the transformation members:
  • Origin is the point on the face (equivalent to Evaluate(UV) );
  • BasisX is the tangent vector along the U coordinate (partial derivative with respect to U).
  • BasisY is the tangent vector along the V coordinate (partial derivative with respect to V).
  • BasisZ is the underlying surface's normal vector. This is not necessarily aligned with the normal vector pointing out of a solid that contains the face, to get that value use ComputeNormal(UV) .
None of the vectors are normalized.

See Also