Hi Burr, the face booleans don't really control depth, instead they can be used to sort of temporarily ignore chunks of the model and only have the booleans interact with just some areas of the model.

I do want to do something in the future for a "limit depth" option for booleans which would then be the kind of thing that you're trying to do in this particular case. But that's somewhat different than an "only intersect with these faces" type mechanism...

The case you have there with the 0.5 depth cut is just sort of a chance thing, when you do a boolean between a solid and a 2D curve it internally extrudes the curve out some distance past the bounding box around the other object which in your case there is just that one face.

So this new "subset boolean" mechanism when used with a 2D curve is still really only about cutting all the way through the target things, not about going to a specific depth yet.

Some things it can work well with though is stuff like only cut through 2 faces making a thin wall like this (2 faces both the inside and outer one you see are selected before doing the boolean difference here):




But notice there that it's cutting all the way through those particular faces, it's not working by being limited by a specific depth value.

So really for doing a boolean difference with a 2D curve as the cutter it's not meant to work with just one outer face of a solid selected like your example, it needs to cut through that face and one behind it to really work properly.

It should be useful more when working with thin walled type objects than just a full big block.

Does that kind of help explain things? I can see that it seems from the result you got there that it is looked like a depth limited thing but really that's just a side effect right now...

- Michael