Trim Surface

Hi everyone, I’m a little bit tired and I have a simple problem that I can’t solve!

I just want to get a surface from 2 other surfaces. I have a surfaceMax and a Border. I want to get the SurfaceMin, wich is the [SurfaceMax-SurfaceBorder ].
It seems easy, but I can’t get it done…I tried Trim and split but it give me just parts. And could you tell me how to do a fusion between to surface? Here a screenshot to help.

I want the inside surface ! I also need some sleep…











Hmm the most straight-forward way would probably be to thicken the border and subtract it with the nifty “Surface.SubtractFrom” node:


En fait, je pense que le problème vient du fait qu’à la base, se sont plusieurs surfaces qui ne sont pas forcément dissociées, alors elles coupent plusieurs fois et j’ai des successions d’intersections.

Mais merci pour la méthode!

Oh !!! Sorry for the french. I’m really tired…

So, I think the problem come from my basic Inputs. I have several surfaces that are not united, I have groups, so they cut not just ones my surface.

Sorry again for the first answer!!!