# Draw Spiral Along curve surface

Hi whoever is out there.

I am wondering if anyone knows how to draw a spiral around a curve surface. I am trying to create a pitcher that has these swirly patterns at the neck. I am uploading screen grab to show what I am trying to do, coz I feel like I do not describe it 100% clear. I have a spiral made now that the beginning and the end radius match the pitcher’s neck, but the sprial lines in-between are still buildup around a straight line rather than following the pitches neck curve.
Thank you

Suggested way 1: Create a row of points where you want the spiral to pass through. Use INTERCRVONSRF to draw the curve through the points.

Seggested Way 2: Create a 2D zigzag curve that follow the path you want the spiral to take in 3D. Extrude the Zigzag curve and intersect with the surface.

So, I’m not quite sure how to do this within Rhino itself, but here’s a way to do this inside of Grasshopper. You could then export the curve back into Rhino. GH definition is attached on the bottom. Let me know if you have any questions!

spiral on surface.gh (53.5 KB)

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No file so can’t tell what kind of surface it is. Try the Pull command which will pull the curve to the surface.

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Hi Annie - make a vertical line on the axis of the helix, of the same exact height. `Loft` the helix to the line, and then 'Intersect` the loft and the pot… any luck?

-Pascal

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Thank you so much Ramon for this gh, which I have added a bunch of sliders and modifiers to experiment with breaking the model in half a dozen ways, which then inspired me to figure out how we got to 3 dimensions at all from a bunch of xy, let alone how it all translated to a 3D helixish curve…
In conclusion, you’re smart and have inspired me to lern math gooder. :-/

If keeping it simple is good enough, just create a profile and use Revolve, quick dirty example screenshots below

Yes That works! Never though that loft a helix to a line will work, but it worked perfectly! Thank you

Pull commend works too! Thank you