Shell failed: improvement in Rhino 6

Another example of Shell failed. Because the shell (0.5 upper face) is not performed correctly?
I hope that in Rhino 6 is improved for this kind of examples; often the intersections are not performed well, for example, in objects tapered, as in this case.
Shelling failed 2.3dm (147.1 KB)

But it is not entirely shellings fault, it is Extrude Tapered, that makes surfaces not suited for shelling (or fillet edge for that sake)

Here is a rebuilt model where the “corners” are rebuilt with trimmed sweep1 surfaces. So now shelling works.

@John_Brock do you think Extrude Tapered could be rewritten for V6 to use better approaches in corner situations?

Shelling fixed.3dm (208.2 KB)

I know that if you use other roads the shelling in this case it works. But it is not possible every time having to redraw everything manually, just because the tapered extrusions give these results.
We should rewrite the tool (and not just this one), it does not work so well for me!

It was not to educate you, but more to shine some light on the actual problem for the developers.

Added to bugtrack list:

Thanks for the sample.

1 Like

Thanks Margaret,
This it’s a very important step ahead.

Another example incorrect.

shell failed x.3dm (326.0 KB)

It seems to be a limit to give for the angle to provide for failture shelling?

In the last example, if it works the offset of the edge of the upper face, because it might not work the shelling?

Needless to make a lot of arguments, the shelling, especially those generated by tapered extrusions, do not always work well. I hope for their improvement in the future.
A good engine intersection, robust and efficient, we would solve so many situations that force users to always having to do everything manually, time-consuming tasks that are useless to waste much time.

I agree, but you have to understand this:

Shelling can not work unless the underlying surfaces can generate good offset surfaces.
EXTRUDE TAPERED makes surfaces not suited for this, so this has to be solved as well.

We also need to understand, without controversy, that many software CAD advancing in a very strong, I think of MOI, solidThinking; are making great strides, Rhino seems a little stuck, heavy, stagnant.
Moi coast quarter of Rhino, and can do about 80% of what makes Rhino. To have a shelling have waited 20 years! If we go on like this, for example, to see the fillet setback, we will have to wait another 10 years from now: crazy!

I hope for a recovery in Rhino 6.
(Sorry for my words, do not want to be disparaging, indeed!)

Thus I say “I agree” to your posts.

I agree that Rhino development seems slow, but to say MOI can do 80% Rhino can! Just to name layout, dimensioning, mesh editing, rendering, texturing, layers, import-export, blocks and etc.!

Come on, Cadmaster, say 70% and not talk about it anymore! :slight_smile:
(I talked about the modeling pure, not to mention other additions)

A simple test of shelling.
I explain why the shelling it does not work when a flat face meets a curved face? (see side edged in red).
In these cases, you might find a solution?
20120612_ShellBug.3dm (803.6 KB)

Another test:
You should work hard to fix this type of situation, where there are tangency between the surfaces, shelling fails!
Will we ever see a solution to these problems?
shell failed_.3dm (256.0 KB)

Perhaps, too much to ask, or impossible? :blush: -(

MOI handles that situations, with those surfaces, so it is not impossible.