Cannot Add/Subtract/Intersect

Problem23.3dm (516.6 KB)

In the attached file I have two solids. I would like to be able to subtract the black from the cyan. However, I get “Boolean difference failed.”

The same thing happens for union and intersection. I was wondering why?

Intersection failure- the first line of diagnosis on failed Booleans is to Intersect the objects and then inspect the resulting curves - in this case there are two locations where the curves are open where they should be closed. Still poking.


Thanks for the tip (I save save all of them you folks give me in a file).

I am puzzled why the problem occurs where it does. The shapes appear rather benign.

I think it happens because the intersection is exactly on a knot line of the revolved surface.
The cyan surface is too sparse - try this:

ExtractSrf the revolve.
InsertKnot, Direction = Both (though I suspect V is the one that counts). Hit Automatic a couple -three times. Join it back up and Boolean away…

(@bigjimslade - fixed, by the way, in the next version (6) of Rhino.)



I was having a similar problem on another assembly and tried this on that one as well. I was trying to Boolean Union a sphere to a part and that was refusing as well. I did this on the sphere and it corrected.

Problem24.3dm (117.7 KB)