Thanx for clear Explanation.
This is the screen of control points first extruded, and second by sweep.
I can not see 4 points in stright direction on sweeped cylinder, may be I did something wrong?
> I can not see 4 points in stright direction on sweeped cylinder, may be I did something wrong?
You're only seeing the control points on the curves there (the line and the circle you used as inputs to make the sweep), not any surfaces. In order to turn on control points of surfaces that are joined at trimmed edges you need to use Edit > Separate to break them into separate pieces and then you can turn on points. See here for more info on that: http://moi3d.com/wiki/FAQ#Q:_Why_does_show_points_work_for_some_objects_but_not_others.3F