why can't I get smooth bottom?
The bottom of the ring on the left is not smooth
The right one is
Please advice what am I doing wrong with the ring on the left?
Thanks
Olga

If you're talking about the pole pinch (red arrow), I don't get where it comes from.
I'm using the same technique as you, and with the provided curves, and I don't have the problem.

Are you using the same building steps ?

- Select a,b,c profiles
- Sweep
- Select the 1,2 rails
- Pick the red curve as railing scale.

Hi Olga, I think you may not have picked the top circle as one of the sweep profile curves.

That circle at the top helps make the shape to be a better rounded shape as the sweep comes to the tip.



Then I believe you should pick the 2 rounded outside pieces as the rails, and one of the side pieces as the scaling rail. (just as PaQ has shown above)

- Michael

Thank you PaQ and Michael for your replies

I have tried the way PaQ adviced and it did work!!! Many thanks

PaQ, I meant the part where the smalest circle is located.
There it was not perfectly smooth. Now it is.

I wonder if I pick RS and the opposing curve for rails and 1 or 2 for scaling rail it turns out differently in this area next to the smallest circle.

Could you please tell me why?
Thanks
Olga

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