Polysurface

When adding a Polysurface (Brep) to grasshopper (object properties says its a closed solid object), i can't perform any boolean operations on it.. any one can help??

Replies to This Discussion

Permalink Reply by taz on October 20, 2009 at 8:21am

Abdul-Monem,

I've noticed that sometimes a closed BRep in Rhino isn't considered closed by GH. I'm not sure why, but my guess is that it's a tolerance issue with the relative proximity of surface edges.

To check if this is the issue you can do one of two things:

You can check the BRep Volume properties. The properties will only compute if the BRep is closed.

You can use a scripted component as shown below. If it returns True the BRep is closed.

-taz

Permalink Reply by biboarchitect on October 20, 2009 at 10:43pm

Hi Taz..
Thanks for your reply.
The bRep volume component gives a result, while the VB is null.
I have uploaded the file
thanks again

Attachments:

001.ghx, 191 KB
001.3dm, 10.4 MB

Permalink Reply by taz on October 21, 2009 at 8:20am

Well the problem is not your object (The VB component will work if you change the name of the output variable to clsd or change clsd to A. You also might have to reconstruct it from scratch for it to work).

Booleans can be a bit tricky, but in your case what you would need to do make sure the Solid Intersection component is receiving pairs of closed objects to boolean. You need to duplicate your reference BRep to correspond to the same number of boxes you want to boolean with.

Below is an example of one pair. Watch out if you try to do all the booleans at once, it will most surely bog down your computer and may freeze it.

-taz