Smoothing non-smooth seams on a polysurface

When I inspect my polysurface using Zebra tool, I see seams in the surface. How can I smooth these seams out while keeping the general shape?

Are you referring to the lines/curves on the surface, which are also visible in Shaded and other display modes? If so those are isocurves, not seams. You can turn off display of isocurves for display modes.
Isocurves can also be turned off and on for individual items using Properties.

Hello - the bad news is, you cannot really, without recreating the object from better surfaces - if you post the model, I’m sure you’ll get some helpful advice about how to lay out the surfaces and make them cleaner.


Thank you and sorry for using the wrong terminology. How may I improve the model with better surfaces? Should I explode everything and move the points defining each face? I have watched others split and blendsrf the non-tangential surfaces, though I would like to learn the more correct way of handling such problems.
Shell 3D.IGS (548.9 KB)

Hello- in my opinion you should use the existing model as reference and make all, or mostly, new surfaces. For instance, it looks to me like you can replace the selected surfaces here


with one cleaner surface



Could you suggest some common ways for replacing a selected surface with a cleaner surface? Or any good tutorials/references on that?

Hi -

There is no easy way. You have to start with clean input curves.

Where to start depends a bit on how familiar you are with Rhino. I see that you posted an IGES file here, so you didn’t make this object in Rhino. If you are completely new, you should go through the Level 1 training manual that you can find from the Help menu in Rhino.

Once you are familiar with basic modeling in Rhino, this might be a good place to continue learning about clean surfacing: