Special "point on a curve" editing

 From:  Michael Gibson
4338.13 In reply to 4338.12 
Hi Burr,

> So the constraint mechanism is tied into using the b-splines
> definition also and not just a single "analysis" created by you...

Yeah basically it works with the fundamental b-splines definition but in the reverse way - the normal way is that a point on the curve is calculated by blending together the control points. The constraint system goes in the reverse direction and says how much do the control points need to be adjusted in order for the point at this parameter on the curve to go through this specific location.

But yeah it works off of the direct b-splines math and isn't just kind of munging points around arbitrarily.


> Wish that spiro curves guy wouldve been interested
> in playing ball with you!!

I kind of got the sense that he was just too busy with his work at Google to spend any time dealing with it. And unfortunately it's licensed as GPL so the existing library can only be used in open source applications.

But yeah I hope to be able to get something kind of similar in the future by adding in some kind of curvature change minimization mechanism to the "through points" type curve drawing.

- Michael