What method surfaces with these rails and profiles?


trying and failing, half profiles, full profiles , it rejects all my efforts.

trying with NetworkSrf

failed with sweep2

I have these profiles and two rails, and need to surface the shape.

What command can do this ?

Perhaps someone can show me result.

I managed the top portion.

Its the upper portion , base of tunnel upwards, of a leather car head rest with tunnel through at neck area.

profiles rails best method headrest.3dm (107.0 KB)



Here is my effort.
headrestx.3dm (353.3 KB)

I used sweep1 using the magenta curve as rail and the red curves as profiles.

I then pulled the 2 blue curves that I didn’t use to the surface with history turned on (those are the green curves).
Then did some point editing on the surface to bring the green curves closer to the blue curves.
I used mostly Scale3d and Scale2D on selected symmetrical batches of control points to bring the green curves close to the blue curves without pulling them away from the curves used to create the surface.

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I recommend you to use the “Symmetrical surface” tool which lets you focus on one half of the model, then quickly make the opposite side mirrored in just a couple of seconds.
byrhinogadget-1010-any-win.zip (1.3 MB)

That plug-in also consists tens of other useful tools. Alternatively, you can download it from the following link:

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Hi Jim,
read this and looked at your file, .

I cannot see any magenta curves though,
and I cann envisage what you did here, totally lost !

maybe a video.

Else a step by step, but I am lost otherwise.

At least I have a model to grab and use., saves the day again.

I would like to fully understand though .

I see curves in same locations varying with each other.

I see my portion dissimilar to yours,
why is that ?

Bobi…Rhino tools, thanks, would need to know how to use what tool on this though.



Sorry I meant to change the dark blue arc to magenta to distinguish it from the other blue curves.

Here is what I started with after the sweep1 (profile curves rebuilt to 22 points). The rest is control point editing.
headrest2x.3dm (193.8 KB)

This sweep1 surface has some unique properties that make it a nice well behaved surface that is easy to edit. It is very close to symmetrical and all the rows of control points in the V direction are lying on their own planes. All of the planes intersect at one point (or line). If use scale2d or scale3d with the point shown in the file as base point you can edit the shape of the model while keeping the points on their own planes. Moving points in then World Y direction (in Top View) will also keep the points on their respective planes.
You can preserve symmetry by selecting matching pairs of points for the edits.

You aren’t going to learn anything about point edit by watching someone on a video. You learn by doing. The pulled green curves with history will guide you. If you move a point and it makes the green curves farther from the blue curves then you know you need to undo and move in the opposite direction. You want to leave the contro points near the magenta and red curves alone. They are already where they need to be.

Yours looked like a dead end. How are you going to connect anything smoothly to that?