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.

But what about the approach of McNeel fixing the bug instead? I can elaborate exactly on how intolerably unnecessary and extra complicated all these workarounds are… I need not only to fix mullions… I have glass edges, putty edges, frame edges, inner casement edges and outer casement edges. All nic…

[image] erik: fixing the bug instead? [image] erik: If it works, that is. You’re assuming it’s a “bug”… that with some virtual screwdrivers and wrenches can be “fixed”. As has been explained above, this is a limitation based on how the current NURBS surface geometry code is written.…

well i had a brief look, and isolating the trouble maker it seems that this edge which is split at 1.5 mm in might be causing the faces to phase out of tolerance when pulled outwards, just a theory of course. if you merge the edge it then behaves. that of course is not a good solution. [image] i …

No I did not assume it being a “simple” bug. I rather assumed that it was a mathematical representation problem. I’ve been using Rhino since v3 and it has always been like this, but it has become a bit better. But never good enough. There must a point when these things are rewritten so that they w…

I’m all for it… it’s mainly a question of where it falls in the priority list and how much time/money it takes to “fix” it.

I’m continuing my odyssey into the weird geometries here (see enclosed file). [image] Both these are self-intersecting curves (they are copies of each other). Don’t ask me how they self-intersect. Maybe it is not important for what happens below. Now explode the right one. And join it. Well … it…

Both curves select if you run SelSelfIntersectingCrv. If you run IntersectSelf on both curves, it will put a point where it considers them self-intersecting: [image] If you undo that and turn on control points, you will see that you have two stacked control points at that corner. How they got t…

Great to know IntersectSelf. Thanks. Now the question arises … How can a curved have two points that coincide ? I understand that there can be two points on the same point in space. But can a curve go from 0,0,0 to 0,0,0 and still be a curve? Without any length? Trying to do a crv starting and end…

It’s not a zero length curve. There is no zero length segment in your profile. What you have there is an open curve that should be closed. The “stacked” control points there are actually the start and end point of the curve. Normally they are “fused” into one point, but that failed somehow. If y…

Hello, thanks for explaining. It would be great in Rhino somehow informed the user about these quirks as they cause problems. Or if the coding of these things changed. I think the two points originated in a dwg-file. Is there a way to “make sure” that the content of a dwg-file is geometrically u…

Weird geometry problem - causing a hard time

Rhino Rhino for Windows

brian (Brian Gillespie) September 2, 2026, 12:41am 49

RH-95260 is fixed in Rhino BETA

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Weird geometry problem - causing a hard time

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