Hi Pilou,

re:
> Why 3dm is different than the Import FBX? (surfaces patches trimed)

It's probably from different options set under Options > SubD import options. You can have
Patch type = "Fewer patches, more control points"
or
Patch type = "More patches, fewer control points".


> Does it possible to have on the same screen, display objects with Edges and
> some objects without Edges ?

Yes, it's possible to hide edges individually. Select the edges you want to hide and use Edit > Hide.
When you do that only the selected edges will be hidden and not other edges that you did
not select.

- Michael