Curves and degree behaviour with join command

Hi All,

I’d like to know what is the logic behind this behaviour.

If you explode all the segments the degree changes again to the original.


Hi Joaquin - a polycurve currently takes on the degree of the highest degree curve segment. There has been talk of making this different… but that is how it is now.


Thanks for the quick reply Pascal.
At least for me this is not ideal.


Hi Joaquin - is this because you want lines to stay ‘rigid’ within a polycurve, so you can move the ends?


Exactly, I have to explode the policurves before editing points to prevent obtaining a curve I don’t want.

I hadn’t noticed this behaviour until today, and I agree 100% with Joaquin. For me the problem is that I’m using the polycurves as a reference for Grasshopper. A possible workaround is to leave them separate and group them together so that activating and editing the points is a bit easier.

Or, since you are using Grasshopper to automate your workflow anyway, just the Explode component directly after your reference.

Sorry for the delay - I hadn’t received the notification…

Yes but I’d need the reference curves to be with different degrees to begin with, and in this case the curves would have the same degree since they were joined inside Rhino, is this correct?

However this is not an urgent nor too serious problem, the important thing is that one is aware of it.


Hi Marco,

If you run the Rhino What command on a polycurve, you will see that the degree of the individual segments is still a part of the definition of the curve. So, when you join in Rhino and reference that in Grasshopper and explode there, you will get the original degrees.

I don’t see how that makes things more easy - when you reference curves in Grasshopper, groups are not recognized and you would have to select every single curve.

OK, that’s great! Thanks Wim, I would have never tried that without knowing

Well the group just makes it a bit easier, inside Rhino, to select all the segments at once to activate and edit their control points - obviously when in Grasshopper I’d have to join them together.