Continue curve command - unexpected behavior


Top: made a curve with 4 control points, degree=3.
Bottom: made a curve with 3 control points, degree=3, then used “ContinueCurve” command to add a 4th control point, but the resulting shape is different and I know no command to make it again exactly like the top one, except than recreating a new one snapping on its points.

Is this expected?
It seems the knots of the “continued curve” follow a different logic than what it would have been if I simply continued the curved while I was originally creating it.

How can I “continue a nurbs curve” by adding new control points after one of its extremities , and have the resulting curve be the same as one that would have been directly created with the correct amount of points?

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Third degree curves have at least four control points, according to my understanding.

True, but the problem is still the same.
“Continuing” a curve will somehow keep old knot parameter and make a sort of “wrong” output curve.

Try it yourself.
Curve A = Degree 3 with 5 point
Curve B = Degree 3 with 4 points, but then add another point with “ContinueCurve” to have the same control points of A

A and B are different in shape.

What is the usefulness of ContinueCurve command?

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You can get the same result by using the MakeUniform command in this case.

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Thank you @Mahdiyar , that’s it.

I think ContinueCurve should have a MakeUniform option to see directly the correct shape while continuing a curve… It would be much more useful, imho.

@Gijs I’m tagging you about this…

Hello- MakeUniform would affect the entire curve, maybe fine in this case but potentially changing the shape a lot if the input curve is not uniform - better to do it yourself for now.
RH-72579 ContinueCurve: makeUniform option

-Pascal

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I understand.

But, if I had the option, I would use ContinueCurve with MakeUniform=true all the times.

RH-72579 is fixed in the latest WIP

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