GetPerpendicularFrames planes changing directions


#1

It is a RhinoCommon question:
I am using Curve.GetPerpendicularFrames(parameter_list) as below. but the planes are choosing direction itself.
I have set origin of each plane to correspondence point on the curve. But planes are some times on the right side, sometimes on the left side of the curve, even though all geometry properties are unchanged. why it is changing sides of the curve , no idea !
I want all of the planes at the bottom right side of the curve.

Plane[] pln = crv.GetPerpendicularFrames(parameter_list);

Hope I could explain. Please some one tell me how to fix this problem. If I could not explain properly then please ask me question.

Many thanks in advance !


#2

Oh! I asked same question before and David answered it
alread. but to me looks like even GetPerpendicularFrames has some problem for identifying planes, all in same side.
http://discourse.mcneel.com/t/why-plane-direction-is-changing-when-curve-tangents-are-same-rhinocommon/21646