Closed vs. Open Polysurface....?

Ive been trying to make cutouts into my project and i had two polysurfaces to make the cuts with so i was trying just use BooleanDifference so it would close everything back without having to manually resurface the openings it made and save me some time. Im guessing I’m just missing something because it would cut out the piece, but it wouldn’t delete the input (was toggled on), but rather it would copy my input in place, so i would end up with a cut out in the piece i was trying to cut, but would also have two untrimmed copies of my input. played with this for 30 min. I ended up having to explode my input, and delete the pieces i didn’t need and then split the one or two pieces i wanted to keep in order to close the gaps. Ive never had this problem before. When i joined the entire piece together it says joined as an OPEN polysurface. As far as i know, i my piece is one solid closed piece, so what classifies it as OPEN? Im guessing a closed polysurface that is hit with a BooleanDifference would automatically trim parts and close itself… Glitch or noob mistake?

  1. The OVAL shaped piece (completely joined together) on the bottom side is what I’m trying to cut out of the larger WHOLE piece (which is joined together)

  2. Wireframe just so you can see that it does go through the piece

  3. This is what happens after i BooleanDifference it. I highlighted only portions so you can see that it created a bunch of random pieces that were never there originally. You can see some half pieces and some larger pieces, that is two completely separate copies of the same thing, but the boolean exploded it like that. That oval piece was originally created with a half circle curve and a straight curve that i mirrored to make perfect halves, then i extruded the curve up, capped, and joined it.

  4. I ended up just using the highlighted pieces that were halved, and just deleted everything else and then joined it all together to get what i needed, but it says its an “Open Polysurface”. How can i make it a closed polysurface or solid?

It would be good to post the file before the Boolean operation so that someone can look… But I suspect that there’s just something wrong with the way you constructed the oval object, it may have overlapping surfaces that are joined together or something like that…

If both objects are listed as valid (Check), closed (SelClosedPolySrf) and non-manifold (SelNonManifold), and the intersection between them is clean (Intersect), then the Boolean operation should be pretty reliable.