surface geometry

 From:  Michael Gibson
2189.2 In reply to 2189.1 
Hi Burr, either method should actually be fine if it produces the same shape that you want.

But I would probably tend to lean towards option b - to fillet afterwards.

That just keeps the boolean calculations to be more simple because there are fewer surfaces being intersected during the boolean operation.

Also some other operations such as shelling can have some difficulty being applied to already filleted objects, so it can just be a good policy in general to try and fillet last rather than earlier.

It's also not unusual to want to fillet some of the edges that are formed only after the boolean, like if you want to fillet the top edges of the pocket as well as the interior parts, like this:

For that you've got to do the boolean first as well.

If you want sharp edges on the top it should be fine either way really but since there are some other kinds of cases that need the filleting to be done later, doing it later is kind of more typical.

- Michael