when I import a sink, for instance, and then wish to intersect the sink model with the countertop to allow the sink depth to be shown, I get a lockup of SU and must relaunch.

this happens constantly.

I can trim the countertop in another way but it it more time consuming. any thoughts?

When I intersect faces I try to eliminate everything that I don’t need (i.e. faucets, knobs, etc.). Copy the sink over and delete everything except the shape of the sink then try intersecting faces with selection. It should run a lot faster.

It’s a good idea to limit the entities that are involved in the intersection. You might try copying just the faces of the sink that are passing through the counter top and then pasting them into the couter to use for Intersection.

How about sharing a SketchUp file with the sink and your countertop so we can see exactly what you’ve got.

It takes more than 8 minutes to cut the opening another way?

Generating intersections is a complex operation that must examine all of the combinations of a face from one set with each face from the other set, determine if there are intersections between them, and if so generate new geometry in the model. If the things being intersected have a lot of geometry in them, the operation can well take some time. For it to take 8 minutes, though, I suspect there is quite a lot of geometry in the things you are intersecting - maybe more than your model really requires.

My guess is that the sink you are intersecting has a LOT of faces (inside and out) that are each having to intersect with the counter (possibly twice, if the counter has depth). This could be a LOT of intersections. Plus, as Dave mentioned, you may be intersecting with other items, if you are not grouping them together and using “Intersect with Context”

If you can cut a hole in the counter without having to intersect, that is probably easiest…