Edge.ComputeDerivatives

Public Class

Returns the vectors describing the edge at the specified parameter.

Namespace: Autodesk.Revit.DB

Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)

Syntax

public Transform ComputeDerivatives(
  double parameter
)

Parameters

parameterDouble

The parameter to be evaluated.

Return Value

Transform
The transformation containing a tangent vector, derivative of tangent vector, and bi-normal vector.

Remarks

The following is the meaning of the transformation members:

• Origin is the point on the edge (equivalent to Evaluate);
• BasisX is the tangent vector (the first derivative);
• BasisY is the second derivative;
• BasisZ is the bi-normal vector (tangent x normal).

Normal and bi-normal are zero if the edge is straight at the point. None of the vectors are normalized.