Why does BooleanUnion fail given a closed extrusion and a closed solid polysurface?

[mike15 (Mike)]

I’m trying to BooleanUnion these two objects:

The cube is a closed extrusion and the other thing is a closed solid polysurface.

Here’s the file.

BooleanUnion Fail.3dm (81.4 KB)

[ivelin.peychev]

Hi,

I believe it fails because your cylinder and box are tangent.

If you move/scale slightly the cylinder the booleanunion succeeds:

It might as well be a tolerance/precision issue.

[DiegoKrause]

In this case and if you can’t move one of the objects as @ivelin.peychev says, you can use _Split first, then extratct the surfaces you don’t need:

and then use _BooleanUnion:

[mike15 (Mike)]

I went with split first, then union.

Thanks for the advice, I’m back on track now.

[lowell (Lowell Walmsley)]

It also works with file tolerance at 0.01
https://mcneel.myjetbrains.com/youtrack/issue/RH-56017