BooleanDifference produces weird result

From a relatively simple shape, I try to subtract a capped cylinder. Both objects are closed polysurfaces, and they clearly overlap:

Screenshot of shapes before the operation

Although Rhino says it’s a closed polysurface, the result doesn’t look like one. It’s weird:

Screenshot of result

A bug?

File for testing: boolean.3dm (150.4 KB)

About my Rhino: Version 5 SR12 64-bit (5.12.50810.13095, 2015-08-10)

Try rotating the cylinder 90° like this.

Then it works fine.

Edit. Odd thing is you can rotate it 180° and it works, just doesn’t like the alignment of the seam you had.

1 Like

Thanks Mark, that works! I know that sometimes it’s necessary to move or rotate one of the objects a little to make booleans work. What surprises me with this problem is that it works but the result is just garbage.

Yes you’d think a surface that looked like this would show up as a bad object or something.


1 Like