Hi Alain,

> It's still not quit perfect (see attachement, use triangles and
> quads. using n-gons is a little bit better).

It looks like there were not a lot of polygons created on that tightly curved area.

What parameters are you using, still only an angle of 12?

If you want to have a smoother look on curved areas, reduce the angle a bit more (move the slider towards the "more polygons" side a bit), bring it down to something like 8 and that will make more polygons on curved areas and give it a smoother appearance.

The angle parameter helps to make more divisions on tightly curved areas - if you have areas that are larger and more shallowly curved then also use a distance value in "Divide larger than" to help refine those kinds of areas more.

Blender's renderer seems to be somewhat sensitive to having much change between each polygon, so you may need to produce a fairly fine mesh if you want to have a super smooth looking rendered result. Some other kinds of renderers are not quite as sensitive.

- Michael