I had a bit of unexpected time this Sunday morning so I had a little play to see how SW handles curved mitres.
Consider this profile running round a segmental arch
Here is what SW produces with a Single Group/Structural Member - a little disappointing!
Any old joiner worth his salt knows that there are two ways around this problem.
The first solution is to cut a curved mitre. I found this way pretty easy, by creating a curved surface passing through the intersection points and using a trim/extend
The second solution is to keep a straight mitre but adjust one of the mouldings.
This again was pretty straight forward by creating an intermediate sketch and editing the weldment profile sketch in the second member, and driving (over-riding) some dimensions with sketch relations
That's the two techniques out of any joinery text book - the thing that surprises me is that it's only for the most high quality work that these solutions are required, normally we just do a straight miter like this, which whilst not perfect is generally acceptable.
Here's SW solution and your average joiners solution on top of each other
By the look of things it appears they construct the miter plane using a mid plane as opposed to the intersection of equally offset geometry
The reason I got into all of this was because at first I used a sweep and noticed SW very cleverly cheats