Is there any way to make it 3D with just these lines?

Is there any way to make a 3D model with just 5 lines in the picture?
I’ve tried some of the methods I’ve learned (network srf, sweep, etc.), but it just doesn’t work the way I want it to look.

post your curves, best would also to explain what your intend is, there may be a better approach suitable. if it has to be exact then you might have to split some curves.

Assuming those are all closed curves, then no, there is no native command that can automagically take random curves and make a clean, NURBS polysurface.

It’s possible they can be split in a way that they are valid input curves for a variety of different surfacing commands.

That’s precisely why @encephalon asked you to post a file with the curves.

Lines.3dm (131.2 KB)
@encephalon @John_Brock
I will upload a 3dm file with lines.
I tried to draw additional lines to express the form, but I still couldn’t make the surface in the way I knew it. Is there really no way?

Of course there is a way to make it, dozens of them, but NURBS have rules, you don’t just feed it random curves with no plan for the surface topology.

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You can try NetworkSrf, you would need to split the curves at the intersections and use the command with each “region”.

But what I would do is model that shape from SubD.

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You missed the key theme in my comment.
@JimCarruthers described it far better.

I’ll try again…
Each surface creation command in Rhino has specific rules and input curve requirements to generate surfaces.
The Help file and Tutorials will help you learn the specific requirements of these commands so you can choose which ones to use for your needs.
I’d recommend going through the tutorials in the User’s Guide found on the Learn page. Go through from beginning to end. They are progressive tutorials and build on what you will learn along the way.

Your initial curves as presented suggest a form, but are not yet organized into a way that they can be used to make surfaces. Think of it as a sketch that suggests a shape. Now you need to explore the different ways to edit the curves so you can use surfacing commands to build it in NURBS surfaces.

That’s the “journey”; to learn to effectively use the tools to create the shapes you want and need.

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Thanks for everyone’s advice! I think I was too hasty in thinking that I should produce results as soon as possible. Let’s go on a journey to learn the surface generation functions of rhino again slowly!


At the risk of complicating this, your curves suggest a form that might be modeled using the new SubD tools.

If your curves are exact, and you need the shape within manufacturing tolerances of those curves, the NURBS surface modeling is appropriate.

If your curves are general in shape and not specifically precise, then the SubD modeling approach might be better.

The two approaches are significantly different in concept and process, but both will result in a manufacturable form.

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This could be a quick approach:

Split your curves at the right spots and make a few Sweep2 / Sweep1 surfaces. Result will be very rough, but then use that as input for a QuadRemesh to SubD:


quick_surfacing.3dm (809.7 KB)

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