Hi Pilou - yup, you don't want to use the segmented sides as the rails, because then you're just back to the segmented-rail problem again.

> Transition between the arc to the side of polygon will be the same
> following bad(if surfaces are not craked) or good sweep?

Yes, the shape along all the edges should be the same in each case - but the internal parts are different.

Even later on when I can make the segmented sweep better, it probably won't be as good as the "good" sweep in this case though - there's sort of an issue of what to do with the profile in the transition between the segments - should it be extended and intersected? Maybe an averagead rotation between the 2 different directions? The abrupt shift of direction in the rails makes it hard to do something good there for all cases.

- Michael