Hi Andrei,

> Circle curves (that was made from circle) that was used to make loft (loose, exact)
> will not give perfectly round surface?

I was thinking you were talking about doing a "loft revolve" something like this:




But I guess you're talking about something more like this:



That way with circles does give you a perfectly round circular shape, but the problem is that you lose the exact control of the profile which Revolve gives you.

Here's a simple example - note how the profile curve has an arc piece in it, and in the revolved result that revolved arc will produce a 100% exact sphere fragment:





This basic shape would be difficult to make exactly if you tried to do it by placing a whole bunch of vertically stacked circle slices in exactly the right spots to try and make an exact sphere shape when they were lofted together.

Hope this gives some more information on why it's not really possible to just throw out revolve and just always use Loft for every kind of case instead. There are a lot of basic mechanical shapes where Extrude or Revolve are just better tools for generating them than Loft.

- Michael