ExtrudeCrve like in Rhino V4

Hi Rhino team

In the attached filethere is the extrusion of two curves, one is made with rhino 4 (black surface) and the other (red) with Rhino 5.
In my work I need to curves on surfaces as in the example that I can no longer do in Rhino 5. Steve and other can you restore the previous mode of functioning with an option or with a command like ExtrudeCrvOld?
Thanks in advance
Ciao Vittorio
ExtrudeCrv.3dm (1.7 MB)

you can trick it in v5 though it’s some more work.

lift one of the control points up on the curve so it doesn’t intersect… extrude curve… then setPt Z on the top and bottom edge of the surface to level things off again.

Hi Jeff
I know this trick but don’t solves my problem when after i use flow along curve with closed curve.
Ciao Vittorio

Run the useextrusions command and set Rhino to not use extrusions.

That people have come up with this “trick” shows a serious problem with something, either not being able to find out how to turn off ‘lightweight extrusions’ or that the whole lightweight extrusion implementation should have (as would seem to be possible) been made entirely invisible to the end user…I suppose it might mean losing those ‘special’ control points for easily adjusting length, but compared to people having to (well not really but how would they know otherwise?) purposely screw up their curves it seems a small sacrifice.

fwiw, i came up with that trick by downloading his file and trying that first thing and it worked… i personally don’t have a need for creating ‘surfaces’ like that.

Hmmm- maybe I am getting it wrong but I don’t think this has to do with using extrusions- the problem for Vittorio is that V5 does not make a single self-intersecting object, surface or extrusion, right?


Hi Steve

The trick don’t solve the problem ,the result is the same. I don’t understand this change of behavior. The command revolve works like in V4 and the surface is not splitted like in ExtrudeCrv.
Ciao Vittorio


If you copy the curve to where you want the other end and then loft the curves you get an self-intersecting surface which I believe does what you want.


Hi Mark
Thanks a lot , it’s ok.
Ciao Vittorio

Hi Vittorio, with the Sweep1 command is ok!
Ciao Paolo

ExtrudeCrv_PN.3dm (1.8 MB)

Hi Vittorio,

You can get the result you want if you extrude with the Gumball>ctrl key method too.

Thanks al lot at all, but i don’t understand because it’s changed only for ExtrudeCrv.
Ciao Vittorio