Is there a way to get the info about the rotation angle for a sweep 1 rail freeform?

[Gijs (Gijs de Zwart)]

Seems like my question was already solved here as well:

Curve frame and curvature?

Looks interesting! I don’t know much about the black-smithing process, do you mean that the bar gets twisted axially into a sort of fusili-pasta shaped thing before being wrapped around the larger diameter form? Does it get rolled into a flat circle shape first and then elongated vertically or do both actions happen at the same time? I think what you’re looking for may correspond to the integral of the torsion of the curve along its entire length… although of course there’ll be all sorts of re…

So in code this would simplify it to:

 result, frame1 = rail_crv.PerpendicularFrameAt(Parameter)
 result, frame2 = rail_crv.FrameAt(Parameter)
 vec1 = frame1.XAxis
 vec2 = frame2.YAxis
 angle = Rhino.Geometry.Vector3d.VectorAngle(vec1, vec2, frame1)
 angle = math.degrees(angle)