Hi Olga, here is a bit more explanation on why a very sharp "cliff" is not so good with a scaling rail.

A scaling rail is applied to a sweep and modifies it by stretching profiles out to meet the scaling rail profile, in this kind of manner:

Original sweep, scaling rail off to the side.



When scaling rail is applied, profiles will stretch out to meet the scaling rail:




If your scaling rail has a very steep kind of "cliff" in it as compared to the rail, it will create this kind of situation:



That's not good because there is like a whole range of areas where the scaling rail intersects the extended profile instead of just one single area.

Even if it was sloped slightly less so that there was only one intersection for each profile to the scaling rail, it will still be doing large jumps in the distance to the scaling rail for just every tiny distance traveled along the path rail. That kind of large jumping is not good for a scaling rail method.

Network uses a pretty different method to create the surface, it is probably going to work better for situation like this which is not good for a scaling rail.

- Michael