Revit 2025 API
FaceCompute |
Returns the first partial derivatives of the underlying surface at the specified point.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)
Syntax
public Transform ComputeDerivatives( UV point )
Public Function ComputeDerivatives ( point As UV ) As Transform
public: Transform^ ComputeDerivatives( UV^ point )
member ComputeDerivatives : point : UV -> Transform
Parameters
- point UV
- The parameters to be evaluated, in natural parameterization of the face.
Return Value
TransformA 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).
See Also