Another Shell failed

Rhino Rhino for Windows
21

Please Pascal, you may check this shell? It is a bug?

22

A simple case of Shell fails. It is very trivial, but it would be interesting if in V6 was correct.

23

if you add a filet and you want to run the shell (as in the figure), also in this case the shell fails. These situations should be correct.

Sorry if I place these examples, I will not denigrate Rhino, are just some ideas to developers, maybe already know these situations …

24

Hi davide76,

The result you want to achieve requires a lot of technics, I will see what I can do. Maybe I can look into it tomorrow.

25

Thanks

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You could check these examples of shell? Thank you

27

The second one works in RH6.
Could you post your manual solution for the first one? It looks like there could be different ways in which this would be “correct”.

28

Another shell failed (Shell face A):
Shell face A failed.3dm (164.8 KB)

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Where does this example work? In the ‘competition’?

-Pascal

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I do not know Pascal, they sent me the file.
I think with UGS NX functions, but are not sure.
Thank you

31

The shell upper face fails (at any tolerance). Why? (The inclined upper face is not perfectly flat, but should it work, or not?).
Rhino wip.shell failed face sup.3dm (69.8 KB)

32

Hi Davide - I see this - it can be ‘fixed’ for now by making the cylinder have its seam aligned to X, that is, lining up symmetrically on the long axis of the top face. The problem seems to be caused by an ugly extending of the inner cylinder.

https://mcneel.myjetbrains.com/youtrack/issue/RH-39283

thanks,

-Pascal

33

Thanks as always, Pascal.:wink:

34

@Pascal - Why is the offset surface a polysurface of two trimmed, overlapping surfaces rather than a single trimmed surface? That may be the underlying cause of the problem. I posted about this V6 behavior earlier today:

35

Hi David - I noticed that as well - I don’t know that that is correct or expected, but I think shell ought to work with the split up surface, it looks to me like extending the surface is what is making it ugly.

I will check on the cylinder offsetting- that does look wrong, thanks for the nudge.

-Pascal

36

(rhino 6 wip)
Another shell that fails.
You can not empty the upper face, that curve.
shelling failed 4.3dm (125.0 KB)

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Could you check this shell? Thanks.

38

Exactly the same error in R5 & R6. As for me, I have no idea why it fails.

39

So you should solve …

40

It works fine if the outer flat surfaces are all simplified into planar surfaces… --Mitch

shelling_succeeds.3dm (203.2 KB)

Specifically, there are two side surfaces that are bad in there - they have crossed rows of control points… Not good.

BadSrfs.3dm (62.5 KB)