Shelling: to be reviewed in special cases

The shelling (the top face) of solid tapered not working properly. Acting on tolerance does not work either, if I’m not mistaken.
The intersections are not calculated correctly.
Shelling failed.3dm(253.1 KB)

in this case, if you MergeAllFaces prior to Shell, it will work properly

Thanks Jeff_hammond

Here’s another situation to solve

Hello Violine, I tried too, does not work in any set tolerance. Command to fix in this case

I also tried it with “Loft”: the surfaces are cleaner, but even in this case, the command shelling is not working properly, you can try it too. This is a case to solve!

Intractable problems in Rhino: some tapered extrusions and their shelling. Some time ago I posted to the newsgroup so many examples of these cases that did not work well: still not been resolved, unfortunately!

I hope that Brian or Pascal inform the developers of this kind of cases.

Absolutely, thanks Davide.

Hi Violine
Look this file .3dm
Ciao Vittorio

Shell_Ok.3dm(126.6 KB)

Hi Vittorio,
I do not know what the problem is, I think as long as the inside circles and respective surfaces intersects it should work,
your model has bigger intersection angle so it works, but should also apply on my model.

All this has to do how Rhino deals with the extension of surfaces - when the angle between them is sharper than a certain value, all breaks down. This has always been a weakness of Rhino, it’s gradually getting better with all of Chuck’s hard work, but there’s still a long way to go.


Ciao Violine
THE attached file tries to explain why shell is not possible geometrically

Ciao Vittorio
Shell_geometri_problem.3dm(591.8 KB)

Some other situations to solve:
Sample files:Shell error 2.3dm(170.1 KB) Shell error 3.3dm(173.4 KB)
Sample images:

Thanks- somewhat of a special case I guess but still, it needs to be handled.

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