Brep plane split component

*** UPDATE 07/2016 ***

Now with capped sides after splitting (if applicable)

Nothing more, nothing less:

Brep + some planes = individual brep pieces.

I hope it can be of help to some of you!

P.S. you need the python for grasshopper plugin, it's free for donwload here.

Cheers,

Arie-Willem

Attachments:

2013_SplitBrepPlane.gh, 4 KB
2016_SplitBrepPlane.gh, 8 KB

Replies to This Discussion

Permalink Reply by Arie-Willem de Jongh on August 1, 2016 at 11:12am

Hi Joseph,

I think it has to do with the function Rhino.Geometry.Brep.CapPlanarHoles that caps the Brep.

Like Alex mentioned, its probably a normals issue.

Cheers!

Permalink Reply by Joseph Oster on August 1, 2016 at 2:26pm

Well, wherever the blame goes, your handy Python component is generating breps with negative volumes, and perhaps other unexpected effects of "a normals issue". I'd look into fixing that within your component, somehow (as I did, for example, with 'DeBrep/Join'). Maybe optional if performance is impaired.

Permalink Reply by ng5 Alex on July 30, 2016 at 9:43am

must be a normals issue

Permalink Reply by Ol OneEye on August 2, 2016 at 6:29am

This is great, but is there away to split with curved surfaces? Obviously the split brep component works, but it is missing the 'split' surface. The only way I have found is to separately split the surface and then rejoin the faces, but that is a pain....

thanks

Permalink Reply by ng5 Alex on August 2, 2016 at 2:43pm

Djordje has provided apossible solution for this.

Permalink Reply by Arie-Willem de Jongh on August 3, 2016 at 2:02pm

Hi,

What Alex mentioned, using Djordje's def. If you want to simply just split using a surface (not do a boolean operation) instead of a plane, use this def:

The funny thing is that it actually converts the plane to a surface before doing the split

Good luck!

Attachments:

2016_SplitBrepSurface.gh, 12 KB

Permalink Reply by Bradley Bowers on August 16, 2016 at 1:02pm

Arie,

I am relatively new to Python and have run into an issue with trying to remove the intersected surfaces from the "pieces" output. (see image want.jpg)

I imagine it would be a boolean difference, but that hasnt worked either. Is there a way that you know?

I have attached two images that I hope explain it

Attachments:

get.jpg, 751 KB
want.jpg, 746 KB

Permalink Reply by Arie-Willem de Jongh on August 19, 2016 at 1:16pm

Hi Bradley!

You're right, what you're looking for is a Boolean operation (Boolean difference). Unfortunately Rhino freaks out when you try to do a Boolean difference on anything but a solid, even when the Cutter you use is a Solid (see image below).

With some extra components you can get the result you want. There are two methods I can think of:

1) You temporary extrude your surface you want to operate on to get a solid. Do the Boolean operation and to finish select the original face(s) you started of with. The last part is the tricky part, to select those faces

2) Use the split component from me and after the split check which surfaces are whitin the Cutter Breps and delete those.
Attached is a def with both options:

Attachments: