Hi Olga,

> Could you please tell me why?

Doing it in that order creates a "steeper" type dropoff for the scaling rail, it is similar to the kind of "cliff" type profile as described here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1807.7

The scaling rail will not tend to work as smoothly when it has a larger zone of it which approaches the centerline at a steep angle.

The link above has some illustrations that try to explain this some more.


Basically when there is a very steep angle for the scaling rail it makes the sweep go through large distance changes for every small distance traveled in the sweep direction, that will tend to not create as good of results.

- Michael