Complex boolean union

Hi all,
I have two -kind of- complex geometries that I want to produce a boolean union with.
This is one of my first attempts to produce a cam file, so up until now I wasn’t so preoccupied with creating watertight solids.
most of the elements have been produced in grasshopper. and it would be a long run to go through the whole process again.
Do you thing that at this point I can save it?
any help will be appreciated.

union.3dm (10.7 MB)

one of your solids is an invalid polysurface. I don’t know how relevant it is but I have bad experience with such solids.

Wasn’t there a way to extract the data tree from a rhino model? You could use that in grasshopper I think so you don’t have to go through the whole process. Never did it just it came in my mind that I read it somewhere.

You can find the Invalid Polysurface with SelBadObjects then take it out to rebuild it with ExtractBadSrf

Check if I succeeded?

Instead of directly applying boolean union I intersected both polysurfaces took only what is necessary, then applied the boolean union.

union_RE.3dm (12.2 MB)

1 Like

So as to be sure I understood what you did:
You intersected the solids, removed what was to be removed and then just joined them right?

No, didn’t join them, I used Boolean Union. Which might be the same result I don’t know. First I used the command Solid->Create Solid

But I realized that it actually rebuilds the surfaces badly, so I used Boolean Union and it worked.


The bottom face of the item on the Finished layer is the problem one. As an alternative approach to the one suggested above you can:

  1. Explode the Finished object.
  2. Create curves from the outer bottom face border.
  3. Delete the two bottom faces.
  4. Create a new bottom face using the outer curve as a planar curve.
  5. Split it using the inner curves where there is a hole right through the object (but not the curve that divided the two original bottom faces) and delete the unwanted portions.
  6. Delete the curves as they are done with.
  7. Select all the objects on the Finished layer and join them.
  8. Union the Finished object with the Layer 01 object - this will now work ok.


Thanks Jeremy!
I already produced the mesh but your message helped me understand where the problem was!

A cleaner way to do this is to

1.ExtractSrf the bottom face and delete it.
2. Cap the remaining object.


Good suggestion Pascal (as always!)