knuckle point in rhino

Does Rhino can define a control point as knuckle?
if yes, how to do it?

thx.

 

For discontinuous slope (aka kink or knuckle) in a degree 3 curve insert two additional control points, one on either side of the control point you want o modify. Then drag each of the added control points to the control point you want to modify. Use "Osnap" with "Point" on so the control points snap together when you drag them.

If you just want discontinuous curvature but continuous slope follow a similar proceedure but only add one control point.

Same proceedure for surfaces except you insert rows of control points and then drag the control points corresponding to where you want the kink.