No result for Boolean Difference

Hi all!

Anyone can tell me why boolean difference is not working on this bezel and shank?
In noob language please if possible :stuck_out_tongue:

Many thanks for the help!
Much appreciated.Diamond Ring.3dm (8.0 MB)

You are lucky that the boolean failed. if it had succeeded you would probably have produced a result you did not want.

The way to handle this is to extract the outer surface and use trim to remove the parts you don’t want and then use join to make it all into a closed solid. (see file)
Diamond RingX.3dm (8.0 MB)

This is an example of of the number 1 reason why I never use booleans in modeling like this. If you use a boolean the best thing that can happen is that it fails. The worst thing that can happen is that it succeeds and you don’t find out until much later that some little unintended part got cut off or added to your model.

In general with complicated models if you reduce the work to just the surfaces that you want to be involved and use trimming and joining it is far more efficient than using booleans and you don’t end up with unintended consequences.

your ring is poking out of the bottom of the part that holds the stone. if you nudge that part down a bit so that the ring is fully embedded, the boolean operation works.


You can just split shank by the bezel. I used that and it worked.
Diamond Ring - Eakan.3dm (8.0 MB)

Yes, and then you can split the bezel with the shank and join.
Trim command has the advantage that it doesn’t leave pieces behind that you later delete.

Hi @Pieter_Goris Pieter,

I believe that your problem is that this part of the bezel and the band share the same space. Parts of them are coincident…ie there is no difference to boolean difference in parts of the two pieces.

Boolean functions like difference to work. The one exception I believe is that planar surfaces (dead flat) in objects that overlap/coincide will boolean. For example these two cubes will boolean union together despite the bottom surface and one side coinciding in parts and having no overlap.

Boolean difference these two cubes and the result shows you what Rhino is doing with these functions.

You can see from the result of boolean differencing the small cube from the large is the same shape…since they had no overlap…but being planar Rhino split the surfaces where they were coincident and then joined it back up leaving the ouline of the small cube in the side of the large cube. Before the boolean the large cube was a polysurface with 6 surfaces and now it has 7.

Hopefully that gives you an idea of why this did not work. If I have something wrong I am sure someone will correct me and we will both learn. HTH.

I am guessing that you were boolean differencing the band form the bezel so that you could produce two parts not one solid? Perhaps so that you could produce the band in yellow gold and the bezel in white? If so I am sure you can modify some of the advice already given to achieve your result. If not just ask.

if you try to use booleans when the volumes come together with a shared curved face then you’ll likely experience a boolean failure.
for instance, this straight pipe and the bent pipe won’t union when they’re perfectly aligned:
(maybe in v6 this scenario will work?)

making your model into a solid is doable still… here’s a quick video showing an approach:

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Thank you all for the well explained examples. I’m learning a lot through here.
Much appreciated!