topic Re: Cut by shell problem in Modeling

Cut by shell problem

Anonymous — Tue, 23 May 2023 14:41:43 GMT

Hello,
I want to cut a wall with a shell object. The problem is that is is using vertical projection of the shell when cutting, and than the lower part of the wall is cut as well (as you can see in the picture). I would like a shell just to be a 'border' for cutting, and not projecting it self to the ground and doing some kind of wired boolean.
Regards,
Pejic

Re: Cut by shell problem

Anonymous — Fri, 12 Aug 2011 15:14:35 GMT

Looks like a bug. It's a good idea to report it to be sure that it get to the right folks promptly.

As a workaround you could make a copy of the shell to use as the operator and extend the eaves so it doesn't make the funky cut.

Re: Cut by shell problem

Laszlo Nagy — Fri, 12 Aug 2011 16:03:10 GMT

Technically I think this is not a bug. It is working exactly as it is supposed to.
But you just found a limitation.

If I see correctly you have applied a Contour to the Shell.
Try to do the same by adding a Hole to the Shell instead of adding a Contour.
Check the attached image.
If you add a Contour, that modifies the Shell boundary that is taken into consideration during the Connect operation.
It seems like adding a Hole does not modify that boundary.

In the attached image I have selected the Hole I added to the Shell. As you can see it does not cut the slanted Wall.

Re: Cut by shell problem

Anonymous — Sat, 13 Aug 2011 00:12:36 GMT

laszlonagy wrote:
Technically I think this is not a bug. It is working exactly as it is supposed to.

I would consider it a bug when something cuts or is cut by a non-solid or void part of an element. It seems to me that the SEOs should use only the net solid volume as an operator.

Re: Cut by shell problem

Laszlo Nagy — Sat, 13 Aug 2011 16:37:58 GMT

The way it works is this: The Shell has a Trimming Body. This can be displayed with an On-Screen View Option if needed. When an element is trimmed to a Shell, the user can decide whether the part of the element within the Trimming Body of the Shell is removed or its part outside the Trimming Body.
In this case, the user chose the part outside the Trimming Body so all parts of that Wall that fall outside the Trimming Body of the Shell is removed.
In this regard the program is working as it should.

So what is important here is that it is the Trimming Body of Roofs/Shell that is taken into consideration in these trim operations.

Re: Cut by shell problem

Anonymous — Sat, 13 Aug 2011 20:14:29 GMT

Thanks for the clarification Laszlo. I haven't had much time to try out the shell tool. So is this trimming body effect on SEOs a feature then?

Re: Cut by shell problem

Laszlo Nagy — Sat, 13 Aug 2011 22:23:48 GMT

Yes, the Trimming Body of Roofs/Shells (not the actual body of those Roofs/Shells) is what participates in Trim to Roof/Shell operations as a SEO cutting body.
This is an important point because if you use the same Roof/Shell in a SEO operation, then the actual body of the Roof/Shell will participate in the SEO operation.
So it is only this new Trim to Roof/Shell command in which the Trimming Body plays a role.

Edit: This video gives some more insight:

http://www.youtube.com/watch?v=fPKrNDXoFHI&list=PL6D2D520FE54A4C95&index=5

Re: Cut by shell problem

Anonymous — Sun, 14 Aug 2011 09:15:29 GMT

Thank you for clearing that up.