Hi Laurent,

> can you point me where are the informations about the edit frame.

Check here:
http://moi3d.com/2.0/docs/moi_command_reference11_French.htm#editframe

There's a lot of information like this covered in the help file reference section, Pilou even made a translation into French!

The reference section of the help file is here:
http://moi3d.com/2.0/docs/moi_command_reference_French.htm


> what are the different step to accomplish what you said ?

It went like this - I changed the units to centimeters and focused on this object here:



I deleted the side wall parts, leaving only the top and bottom surfaces:



I had previously tried to build a planar surface by drawing in some new lines between the corners but that failed, which indicates that the ends of those surfaces are not fully planar with one another.

So one way to fix that is to turn on surface control points (Edit > Show pts), and select these control points:



Then switch to the top view which will look like this:



Now it is possible to edit those points to flatten them down to all be on one exact same plane rather than having them kind of slightly jittered around like they were previously. To do that grab the corner grip of the edit frame (the edit frame are the corner grips that show up around the current selection that allow you to scale or rotate it):



And then drag that down to flatten the frame, there will be a "flat" snap that engages at the collapsed point, like this:



If you don't get any flat snap then it means that it was already totally flat. But your object here was not, that's one of the things that was likely causing some of the fillet problems too.


> for example when i tried to squish it until i see the "snap"
> and i want to go back to the original position i can't snap to
> it. i have to undo to have the original back.

Sorry, I'm not really understanding this part.

If you drag something to move it, it is normal that you don't have a snap available at it's old previous position, if that old position was just out in space somewhere with nothing there anymore.

If you want to get back to some spot later on you generally need to place something there to serve as a marker, a point object can work well for that (Draw curve > More > Point).

Hope this helps!

- Michael