Span Tolerance for Inserting Knots in NURBS curve


I’m having a problem with inserting knots into a nurbscurve. The original knot vector is […,4.38816991,4.38816991,4.38816991,4.3881700452521,4.3881700452521,4.3881700452521,…]
The knot to be inserted is 4.38816997743766. The function InsertKnot() returns true, but the knot vector is not changing. I know that these values are very close. Even the span is not recognized by Rhino. I assume this is because of a certain tolerance. Is it an absolute tolerance or a relative?

Is there a way to work around this without generating a completely new curve, e.g. by scaling or shifting the knot vector? The original curve was derived with Rhino but the knots to be inserted are defined elsewhere and I cannot change this.

Thank you!

Hi @am.bauer,

Can you provide some sample code, that we can run here, that is not working for you?

– Dale

Hi Dale,

I cannot reproduce this error today, also when I reverted the code to the previous version. So I guess it’s fine for now. Sorry for bothering and thanks anyway!