Bug? Boolean Intersection

In this file i have two closed polysurfaces. If I try to do a boolean intersect on them, one of the surfaces just disappears.

Problem Intersect.3dm.zip (112.8 KB)

You can get the desired result by copying the disappearing polysurface to itself to make wider then intersect.

Problem Difference.3dm.zip (167.1 KB)

Here’s a similar problem from the same shape.

If you do BooleanDifference RED - PURPLE

Purple simply disappears

If you run Intersect on these two objects and inspect the result, you will see why this type of stuff doesn’t work well. The intersection doesn’t form a complete, closed loop with which to trim. IMO, BI should just do nothing in this case.

But shouldn’t it give a message that it could not do the intersection?

For me, I am getting silence.

Hi -

Probably, yes.

You are not getting silence but a buggy result. I assume that you have the DeleteInput option set to Yes - the output of the command is visually identical to one of the inputs.
I’ve filed this issue at RH-65143.

Also note that your file tolerance is not the recommended one order of magnitude smaller than the smallest feature in the file…

Definitely, you can get around this by changing the tolerance.

I just save odd behaviors whenever I see them.

Then I move on to correct what I am doing wrong,.