Shelling does not run properly

The shelling of this object does not run correctly, you might take a look at you?
shelling not executable correct.3dm (271.8 KB)

Hi Davide,

I’ll file this example to see if Shell can account for it. In the meantime, if you construct the solid with a Sweep2 as shown, you can shell it at some wall thicknesses successfully. At large wall thickness values, the inner surface will cross itself however so watch out for that.
shelling not executable correct_2.3dm (970.1 KB)

Thanks BrianJ, with the Sweep2 working properly, but building the figure with a tapered extrusion nothing to do!
To control.

Brian, I tried using similar forms generated by tapered extrusions, and the shelling does not work. Conversely, if you use the command Sweep2 to do the same forms, the shelling works well as it should.

Agreed… I filed the bug and noted that I thought it was due to the triangular surfaces created by what I assumed was a tapered extrusion. Remember, all surfaces are four sided in their control point structure. Even these triangular ones will have a fourth side where the points are coincident. These areas can cause all sorts of issues.

Yeah, just fyi, Davide, as far as I can see the problem is in the little wedges at the extended parts of the offset curve- if these are replaced by planar surfaces (extract one, and Cap, etc) then Shell handles it OK.


I understand. They are small situation that should, in my opinion, be answered in Rhino 6; nothing serious, but if the software did the job for us serebbe better!