Is it possible to get the manipulator position (orange) from the corresponding SplineHandle object? I'm able to get the spline end point (black) position from the SplineHandle object, but can't seem to get the manipulator position. The only way I'm aware of gaining access to the manipulator is through the CreateManipulator method.

I'm trying to get the value of a vector which is tangential to the spline and starts at the spline's end point (which is why the spline handle seemed like a prime candidate).

Another consideration is to create a construction line, make it tangential to the spline, merge points, and then get vector from endpoints. However, I'd prefer to not add any more physical components and use a purely calculated approach instead.

From this, do you have any advice for getting the desired vector direction? Thank you!

I was able to find a workaround by using the GetCurve method on the SplineSegment and then using GetBCurveParams5 on the resulting Curve to get the Curve's SplineParamData. The Spline's control points can then be taken by calling GetControlPoints on the SplineParamData object.

I then used the control point location closest to the Spline's endpoint to get an approximate of the desired tangent vector.

Curve segmentCurve = (Curve)currentSegment.GetCurve();

SplineParamData curveParams = (SplineParamData)segmentCurve.GetBCurveParams5(false, false, true, true);

object controlPoints;

bool statusTest = curveParams.GetControlPoints(out controlPoints);

double[] controlPointDoubles = (double[])controlPoints;