Wish: Find Kink Points

It would be nice it there was a way to distinguish kink points from standard control points when points are turned on for a curve, in those cases where there is no obvious visual kink. These show up a lot in derived curves, and I like to remove them so objects I create using those curves have fewer seams. Perhaps Rhino could represent them with a little right angle instead of a square, or make them larger or hollow, or use a contrasting color. Failing that, a SelKink command could be useful.
There are times when I want to keep some kinks but remove only unnecessary ones, where MakePeriodic or Rebuild can’t be used on the entire curve.

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Hi Mark- kink-location control points (fully multiple knots, or degree number of knots at that location) will lie on the curve, so that is one clue at least. Do you delete these, or RemoveControlPoint, or RemoveKnot to clean up?


I do look for points truly on the curve, but often they are hard to tell from points which are just very near the curve without a lot of zooming. I just delete the kinks, and if the curve changes too much I add back a standard control point and adjust it, which seems faster to me than using RemoveControlPoint or RemoveKnot. I commonly drag a suspect point and then if it kinks, delete it, if not, undo drag.

Hi Mark- if the kink is already slightly kinked, then CurvatureGraph can help locate these also but I"ll see if I can cook up something in the way of a script or something. You can also do something like Explode the curve run CrvStart on the results. Macro, for a pre-selected or post-selected curve or curves:

Explode Pause
SetRedrawOff SelNone SelLast
CrvStart SelNone
SelLast CopyToClipboard
Undo Undo Paste SetRedrawOn

'course these are points that look like control points, so not as good as a script, but maybe OK for now.


If I first go into Options/View/DisplayModes and set the point object size up a few clicks, then that macro comes pretty close to the effect I was looking for. Thanks!

Pascal, I requested something similar a while back and you were kind enough to write a script called DeKinkCrv (I think). I STRONGLY believe this should be a stock tool. I have to do this all the time, and the manual technique is excruciatingly slow.

I’m traveling at the moment, otherwise I would just post it. Maybe you still have it in your script library?

I would be interested in that script, as I use the above macro often.

Sorry for the delay - I’ve been out of the country… Here is that script.


DekinkCurve.rvb (855 Bytes)

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+1 for this to this to be a stock comand.