Hi Luis, here is an example that's a bit less busy that shows Scale1D in use for this kind of thing:



There you can see how the curve responds during the Scale1D steps - once you have picked the first reference distance to be locked on to the particular spot, then the last reference point will let you track that point to the new spot.

Was that the kind of thing that you want to do?

One other note - the curves in your file were just slightly non-symmetrical, like the orange curve was slightly not in a vertical plane. So I tightened them up just a bit which gives cleaner kinds of snaps. If you see things like a perpendicular snap is slightly not in the same spot as an intersection where you would expect for them to be the same, it probably means your curve is slightly not symmetrical or planar.

- Michael