Smooth blend surface options...?



I’m looking for the best way to joint two free-form ends of a tube so that the surface of the pipe connecting them will flow seamlessly between the two extremes. When I sweep one rail with the two profile curves of each end respectively, there’s a kink. When I just pipe the curve, and then pull away each end slightly to later blend the surface, there are still kinks/obvious visible markers where they are joined. I feel like this is something simple to figure out…any ideas?

Thanks! 1 004.3dm (4.1 MB)


I would start with changing your approach. Your model is overly complex to begin with. There’s no need to model the main body as polysurface. Modeling it as one surface will allow you to point edit it to explore a greater range of forms, by moving and scaling the cv’s. You can add more cv’s later to add detail. Good models start with good curves. Your curves are cv dense polycurves. Always save the fillets/blends for last.

1 005.3dm (4.6 MB)


thanks stratosfear…there’s a lot of stuff that i’ve learned just posting questions on this forum and reading through other people’s questions/comments…with that comes some stupid questions.

how can i model it as a single surface? i can rebuild the central connecting surface and turn control points on, but if i join it to the othersi no longer can.



You can’t point edit polysurfaces (multiple surfaces joined together). You can explode them then point edit the individual surfaces. You might consider looking into t-splines for Rhino. It’s a polygon modeling plug in. It will allow you to create and point edit complex organic shapes like yours. Then convert them into nurbs polysurfaces.


Yeah, I know there’s no point editing for polysurfaces :frowning: and unfortunately I don’t have t-splines. Was hoping for a way in Rhino with what I’ve got (the end surfaces are from another model and was trying to join them)

(David Cockey) #6

Some manual adjustment is needed. Reposition the ends so that they are better oriented with the large center surface, or modify the curve used for generating the center surface so it and the ends are better oriented with each other as Stratosfear showed. Get the right orientations between the ends and the center surface and you will be able to have them flow together very smoothly.

(Marc Gibeault) #7

There’s point editing for polysurfaces; SolidPtOn, but it’s not of much use in situations like these.
And you should be able to model this very simple and fluid geometry very simply, there’s no need to go into plugins before you master basic stuff.