Isolating specific faces from a list of breps

Is there a way where I can isolate specific faces from large numbers of different breps?

I have a design that I want to laser cut and only need a specific face of each of the breps:

I can do this by de-brep the entire model but am struggling to find a way to isolate just one face out of each brep, specifically the face which will be on the laser cut layout. (Highlighted in yellow). For the horizontal breps I need the top face and for the “ribs” i need either the left or right brep.

face from list of (500.8 KB)

Hi -

You can sort them all by area and take one of the two with the greatest area:


There are many ways to do this. Which solution is the best depends on if and how you are going to change the existing geometry later on.

In most situations you would probably first filter the Brep which has this surface.

Then extract the face you want.

PS: your object is symmetrical but not built on the origin / world coordinate axis system. It makes sorting a tiny bit more complicated. I would build something like this on the origin whenever possible.

face from list of (522.5 KB)


Thanks! The model was built from a single point at the origin but relates to the corner of the bottom square. But could remodel it so the origin is the centre of the moedel, thanks for the tip:)


A couple of things I noticed while looking at your model.

If you want to sort the faces of your breps by area, the horizontal breps have a larger bottom face because of the way your joints are cut at an angle.

Also, if you’re planning to laser cut and assemble this you should re-examine the way you’ve designed the joints.

In your model, the purple area shown above is empty.


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