Heya I have just moved to V8 from 7 and a weird situation is happening with Sweep 1 rail, in cases where the path comes back on itself and passes within the profile it fails to complete the surface. If I move the profile away its fine. Both path curves have been refitted to tolerance and had ma…

This doesn’t work in Rhino 7 either here. Sweep1 code hasn’t been changed for long AFAIK.

You are right, yep it has stopped in 7 as well now. The weird thing is I have done about 30 of these types of curve with no issue, even knots like clove hitches that are fine. [ones ok] [hitchs]

Any idea what’s going on with it?

In your last image I don’t see anything that is close to what you showed in the file. I assume you are after modeling something realistic, so I don’t see the purpose of a self intersecting rope. If you have history enabled, maybe you can tweak your rail curve a bit until it works, or use pipe as y…

You could split your rail curve at the circle’s location. Then it works. Maybe a workaround. [Untitled-41]

I can assure you I have good reason for needing it done like this, I have been doing this sort of work professionally since 2004 and been using Rhino since v2 so I am not a newbie by any means in case it seems that way. The object represents a spliced eye Stirrup which unlike a served eye is woven…

@Richard_Dunn I can certainly write up a YT for this, if you want to. Just trying to understand if there is another way to get your work done. If it is for making images only you could also use curve piping mesh modifier. If you have older versions of Rhino where this type of Sweep1 works then we …

Hi Richard, If you think about it, there is nothing to link the profile to the rail apart from its physical position. If you place the profile in a region where there are two adjacent sections of the rail, Rhino has no way of knowing which part of the rail to associate the profile with. The trick…

Yeah, interesting idea, but it has worked for about a hundred exact other cases, it’s just 2 or 3 paths that fail., but I have been running the sweep with a detached profile onto a centre based path the whole time. Also as I showed in the test curves I attached. if you do the same principle on th…

[image] Richard Dunn: Yeah, interesting idea, but it has worked for about a hundred exact other cases, it’s just 2 or 3 paths that fail. Upload one of the “exact other cases” which works, and someone may be able to see what is different.

Sweep 1 Rail not completing along full path

Rhino

brian (Brian Gillespie) September 29, 2026, 10:19pm 18

RH-92232 is fixed in Rhino BETA

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Sweep 1 Rail not completing along full path

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