Curve on surface quality. How to do?

I drew a surface and projected (adapted) a curve of grade 5. The curvature graph is performing well.
Then I extend the red edge of the surface with the “smooth” and “merge” option and extend the curve over the entire surface (ExtendCrvOnSrf).
The curvature graph, in the stretch of extended surface does not show a good trend.
Quality curvature.3dm (76.2 KB)

How can I improve everything by making the whole curve on the surface continuous (g2)?
(Bug? Rhino command limit, or my lack of capacity?)

Hello - It looks like that is a limitation in that tool - extensions seem to be g1 only.


Thanks Pascal,
i thought it was my problem.
It would be interesting if I put this issue to the attention of a developer; Rhino needs improvement!

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Multiknots strike again.

I don’t think it’s just a multiknot problem… the graph is always disastrous!
That’s why many users use Alias, Nx or Catia.
If you can do better let me know …

The answer is (as so often) VSR/Autodesk shape modelling had a curve projection tool, that projects curves to surfaces resulting in smooth bezier curves and telling you about the deviation from the surface.

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In fact, the tools developed not optimally give this kind of results.
And in these examples that Mcneel must have more attention, providing more quality …
I don’t think it takes millions of dollars or thousands of developers to do this … you need planned action and a willingness to head in this direction …

I wonder:
after the late VSR (now no longer available for Rhino), why doesn’t anyone want to invest by producing a class A modeling tool set to combine with Rhino as a plug-in?

They develop everything from SubD (Clayoo), to BIM (VisualArq), etc.
We would also need a plug-in that can also do better the Fillets, like “NPower” … it would be a dream!
You “XNurbs” developers, for example, who are so good, why don’t you think of a set of commands similar to VSR, in addition to your excellent multiblend?

In a previous discussion about VSR someone who knew the developers of VSR said the number of purchasers was small.

To improve the curve.
Divide the curve into a large number of points. I used 101.
Pull the new curve to the surface.

I agree that the ExtendCrvOnSrf tool needs improvement. There is no reason multiknots should be used when extending a curve on a smooth surface.

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This tool, like many others, needs improvement. It could be a starting point…
I refer to situations like this when I say that I would like to see improvements in “classic” tools in Rhino and not just SubD, Grasshopper and rendering.
Many attack me, but they should look beyond my words; they should not misrepresent the meaning of my speeches which are for good and not empty criticism…

If a command was born, for example from the time of Rhino 4, it is not said that it must remain the same for many versions … If Rhino wants to become really performing in many fields it should decrease the gap with other Cad, otherwise it will always remain behind …

For the love of god, take down the pathos levels a notch or two…
And don’t worry, we all secretly love you.
This place wouldn’t be the same without you… :cupid:

Thanks for your love :smiling_face_with_three_hearts:, in life it takes pathos, otherwise it would be a flat, sterile and feeble life.
Peace and love for everyone! eheheehheeh :joy: :joy: