Deformed Half Sphere - looking for advice

Greetings fellow Rhino users. I have come across a problem with modelling a deformed sphere in a clean manner. I’ve tried various methods to make the curves into a clean surface, the only one i had any success with is Network Srf. However I can only make it work on one half of the sphere. When I join the 2 halves, the curvature between the 2 halves is not clean and presents a break.

Any tips to create a nice clean curvature continous surface would be much appreaciated!

deformed sphere.3dm (2.6 MB)

I’d start with a rebuilt sphere cut in half (degree 3, 8 points in both directions in this example):

deformed sphere simple.3dm (177.6 KB)

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Thank you for your example. That’s a very elegant solution. I mistakenly named my topic sphere (now edited), I was actually modelling a demi sphere, and it’s the 2 halves of this demi sphere which did not join up very well. Your model works a lot better, however it doesn’t match the curves perfectly. My problem is that i’ve already launched the fabrication of this shell using the curves, and I now need to integrate structural elements which reference a clean 3D model!

I presume you made a sphere, rebuilt it with more points, cut it in half and dragged control points to line them up with the reference curves?

Thanks again!

basically that’s the process, yes.

You can rebuild/refine (_Insertknot is a good way to refine while keeping the shape the same)

What’s your tolerance towards the curves?
Also notice that exact matching will not be possible due to:

Other approach with one networksrf:
Notice in this file how the curves are sorted / joined in two directions

deformed sphere networksrf.3dm (3.8 MB)

If tolerance is not super-important (read if it’s for visual use only, and not for manufacturing) then Patch’ing two circles can also give a good result.
Or make it in SubD.

Looks clean and precise, thank you so much! Looks like I need to start increasing rigour with the curves to begin with :wink:

I would use either “Revolve” (for perfect circles) or “Rail revolve” (for non-circular shapes). Simple to edit with a History-enabled profile curve. Note: Works if the goal is to maintain the height of the object.

Looks like in your case the solution by @Gijs is good for shapes with irregular top shape. If you want to be able to match two mirrored half spheres, then I suggest to split the sphere across its other direction, leaving the end points in the middle, then split the sphere in half and crop it.