Boolean union makes one object disappear

Rhino Rhino for Windows
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boolean fail.3dm (534.6 KB)

Can anyone tell me why this won’t boolean? Both are closed valid polysurfaces, no naked or non-manifold edges…

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Hi,

I’m seeing the same. I opened an issue here.

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boolean fail.3dm (490.6 KB)
Sometimes booleanunion might not work, but I managed to join your solid by deleting the sufaces touching and joining them directly

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Thanks!

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Thank you. I find Boolean operations fail often, and for no visible reason, normally when surfaces occupy the same space as each other. Instead of moaning to my colleagues I’ve resolved to upload them. Normally the issue can be solved by offsetting surface slightly or moving one of the objects slightly-but it’s annoying.

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Hi Martin - generally Boolean operations will work with coplanar faces - not in the example you posted… and will not work with non-planar coincident faces. My guess of the moment is that the problem may be here
image

there are two very short edges threre. Josh will figure it out, but that is a little un-clean there you might want to have a look , assuming it is not there by design.

-Pascal

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Thanks for your reply Pascal, could you expand on what a non-planar coincident face is? Maybe with an example? Thanks.

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Hi Martin - say a cylindical face or any freeform face that is shared or partly shared by the input objects - they may work but it is les reliable. I must say though in my quick tests just now, it works better than I remembered.

-Pascal

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