Thank you for MoI! I have some questions.

 From:  Michael Gibson
474.3 In reply to 474.1 
re: Groove on a box

This is an interesting problem - sometimes it is pretty difficult just from a design standpoint to imprint something smooth onto something that is not smooth.

The examples that you show are definitely grooves in the object, but I think the part that you don't like is the juncture where they join up.

Basically if you want a smooth looking result, you're going to want to try and model a smooth sweep to get it.

I've attached here one model that shows a workflow which seems to be ok. One thing that seems to be important is you probably don't want a groove that bites out exactly half a circle's worth of a chunk, because that magnifies the sharp areas in the transition zone. If you only cut a more shallow portion of a circle out of your base object it seems to be closer to what you might want.

So to start with I draw a box and half a curve. Then I mirrored the curve, and offset the box by a little bit. I offset the box so that the sweep that I generate will intersect the original box in a more shallow manner.

Trim the larger box with the curve and join the pieces back together, then extract the edge curves. There are a couple of methods for edge curve extraction - you can select them and do a ctrl+drag on them to duplicate them, or select them and do copy + paste.

Then I drew a sphere at the corner, and duplicated it to the other corners using Transform/Copy.

Trim the curves with the spheres to cut them back a bit and discard the corner spots. Now do blends (select near the ends of where you want to blend) to create one smooth continuous path and join that all together. Now sweep your groove along that and boolean it out. You can also apply a fillet to the result to round things further, it looks like the maximum it will take is around 0.25 before some pieces start to run into each other (which prevents the fillet from working when that happens).

I think it may make sense to have offset the box even a little bit more, or use a smaller radius circle for the sweep, to make the groove even just a bit more shallow.

The other thing that can really make it easier is if you fillet the box first so that there is a round edge there instead of a totally sharp edge, because otherwise this corner piece here:

is kind of hard to get rid of - that is the one that gets magnified if you have a half-circle groove instead of a more shallow one. I guess it might be possible to do another sweep of a piece that kind of grazes the edge there to try and boolean off that corner with another operation...

Anyway, hope this gives you some ideas...

- Michael