Vector of a line C#

I want to find the vector of a input line, how do I do that in C#?

If you know* that your Curves are linear you can cast, or recreate, them as Lines, or directly recreate as Vector3d, like so:

  private void RunScript(List<Curve> L, ref object A, ref object V)
  {
    Curve crv = L[0];
    Vector3d vec = new Vector3d(crv.PointAtEnd - crv.PointAtStart);
    
    A = crv.PointAtStart;
    V = vec;
  }

// Rolf

* Well, you can recreate them as lines anyway. You can also test “crv.IsLinear” if it matters whether the cruve is linear or not)

If you want just line and not curve choose Line as Type Hint


in Line you will have direction as Properties
A Line could be a Curve but a Curve is not always a Line.
https://developer.rhino3d.com/api/RhinoCommon/html/T_Rhino_Geometry_Line.htm

You don’t need to create a new vector at all, the subtraction of two points should already give you a vector.

.Direction would work if the data type was line rather than curve.