A process ;) Flatten must be made in FRONT FACE !!! (and reading begin by the Bottom to Top sorry :)
@Michael : I don't use the extrude method in case where all sides should be inclined (so to much cuts)
As I obtain 2 surfaces I can easily make a sweep 2 rail between them even inclinations :)

>Then go to the Front view and use the edit frame to flatten them down to be planar

Wow, how did I miss this feature of the edit frame? Another example of MoI's understated brilliance. :-)

Jesse

Hi Pilou,

> that's this! I have tollally missed this paradigmatic thing!!!
> It's an Earthquake for me! :)

Yeah it's one of the big differences with NURBS as compared to polygon modeling - NURBS can have Trim curves that trim away parts of an "underlying surface".

There's some more description of this here:

http://moi3d.com/wiki/FAQ#Q:_Why_does_show_points_work_for_some_objects_but_not_others.3F


> From what comes the measure of the length? I have only half of the form!

It just comes from whatever was the original surface before it was trimmed or booleaned.

So in this case for some reason the original full surface was trimmed by only half of the curve outline, so when removing the trims it restores the original full part, which is convenient for this case.

- Michael

yeap I have translated that but don't yet make a connection with a concret case! ;)
Now that is done :)

I believe that an another method with sweep with 2 rails can also works : just drawing good angular sections at each direction change