Locking one part of a surface while editing the other


I have a surface, that I would like to make some cracks in it and then control every edge separately (like in the attached drawing). In reality it is very simple - just cut, and then then glue one part and lift the other part, but I couldn’t find a way to do it in rhino…

Does anyone know if it is even possible?

Thanks a lot,

You should build the whole thing from two or more network surfs and lift just the desire edge curve

Hi Adi- is any of these (simplified, I’m not quite sure what you are asking) in the attached file something like what you want?

Lift_Maybe.3dm (221.6 KB)


Thank you very much for the answers, but what i want is actually not that - I attach a photo of the physical model I made - what I need actually is to create a cut, and then to control only one part of the surface so that it will be lifted, but the rest of the shape will stay the same

Hmm- I’m not reading the image very well- how about this one, is that closer to what you want?

Lift_Maybe.3dm (63.4 KB)


Yes! that is exactly what i want!!! how did you do that…?

Thank you!!

Hi Adi- as you can see in the Rhino file, the ‘lifted’ part is a separate surface.

  1. Wiggly curve on the surface.
  2. Offset this curve (or draw another curve if an offset is too rigid).
  3. Add lines between the ends of these curves to form a closed loop if curves.
  4. Trim the plane with the curves, leaving a hole of that shape.
  5. Either lift the control points or the whole of the original curve upward to form the shape of the lifted edge.
  6. Loft the ‘lifted’ curve to the curve from step 2 above.
  7. MatchSrf the lower end of the loft to the trimmed surface edge there. Match for Curvature, and set 'Preserve other end ’ to Position.

any luck?