Hello, I have this really weird thing going on with “mullion” geometry causing BadObjects after a couple of “MoveEdge” operations. I have this closed curve shape, very clean and neat, with only a few control points: [image] I extrude this to a prolonged shape. [image] Let’s say 200 mm. I ma…

[image] erik: Awful mess this. It’s simply not a good idea to rely on methods that move edges and the like unless you are working with principally planar-surfaced objects.

mullion problem 260430.3dm (5.6 MB) Here’s the file. And SystemInfo: Rhino 8 SR29 2026-3-4 (Rhino 8, 8.29.26063.11001, Git hash:master @ bbd126f84fcdaf7a974615b7c9f4f8667571c147) License type: Commercial, build 2026-03-04 License details: Cloud Zoo Windows 11 (10.0.26200 SR0.0) or greater (Phy…

The simple answer is that MoveEdge and other similar “Solid” operations do not work reliably when they involve edges of non-planar surfaces.

Hi @erik6 This has - to say it midly - been around for a while: Bug: direct editing fail . Post is from january 2015. Cylindrical faces in Rhino are totally hopeless when it comes to direct editing. No improvements in the WIP, unfortunately. -Jakob

Well, could McNeel suggest a workaround ? /Erik

Maybe skip using Rhino’s bug-afflicted “solid modelling tools”, and try to do what you want to do with Rhino’s rather solid NURBS surface modelling tools instead? It’s easily done in Alias or Catia, and very likely in Rhino, too. Maybe upload the initial section in your OP?

Hej Erik - [image] erik: could McNeel suggest a workaround ? A workflow using history and Boolean operations could possibly be used: [image] How to model a Camera in Rhino Tutorials [BooleanModeling] Background Recently, @sfp posted a question asking h…

Hi @erik6 I usually just extract, join and move the end caps and scale the center part into oversize and trim/join or CreateSolid - see vid for reference. HTH, Jakob

Completely doable, but quite cumbersome. I wonder if this is a mathematically unsolvable problem? Or if it something else that stops McNeel from solving it so that we can work with a more natural workflow? McNeel! Any answer to this ? Thanks /Erik

I did upload a file with the original profile now.

Wim, yes it might be so, that it is possible to do it dynamically. But the simplest solution is to get the Boolean Operations fully functional. And the question remains: Is this a mathematically unsolvable problem or is it just something that is hard to fix? (because the geometry is described in …

Weird geometry problem - causing a hard time

Rhino Rhino for Windows

wim (Wim Dekeyser) April 30, 2026, 10:47am 7

Hej Erik -

A workflow using history and Boolean operations could possibly be used:

-wim

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Weird geometry problem - causing a hard time

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