Hi Nick,

I can't think of a better way in general... If your curved surface is a straight extrude along one direction, then you can work with curves instead of surfaces (like offset the curve, and cut using the curve profile), like Brian has in his screenshots.

But for a totally general curvy surface where you want the top to follow in an offset manner, I think you've got the best way to do it there.

I've thought a little bit about trying to extend the Extrude command to handle making a protrusion or a cut into another object as a built-in function of extrude. Maybe that could include this kind of "offset cap" as an option, but there are some difficulties since that style doesn't track along with the mouse along a single direction like a regular extrude does.... It's something that I'll try to think about when I get a chance to work on Extrude in the future.

- Michael