> It's a very hard work when you have many
> points! (conceptual of course)
> It's because I had make the trimming above (ellipse
> trimmed by vertical lines) ;)

Hi Pilou, it is not so hard for your example - if you need help you can turn off all other snaps than End snap. You can do that by going to the menu that pops up when you move your mouse over the Object Snap button and right-click on "end" to enable only end.

Here is a demo with your particular case - total time is 12 seconds, is that really a very hard work?




If you do only want to get those points, I would suggest drawing in a point object initially rather than using vertical lines as the cutting objects as you have done here. See this previous example where I use points:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1634.9

If you want to end up with points there, then why do you use vertical lines? Why not just use points and then you will have points where it seems like you want them.

- Michael