Hi Tony,

> unfortunately my wireframe is more complex
>
> I have to create a wooden surface of 4 cm with this form

You probably want to do this in smaller pieces. Try selecting your current wireframe and using Edit > Separate to break it apart into individual curve pieces.

Then add in some connecting lines like this:



Now you have some 3 and 4 sided regions which can be surfaced by selecting the outline of each individual region (just one region at a time) and using Construct > Network, like this:





Then go on to the next region:



etc...


You can't easily do a shape like this all in one single run of a surfacing command due to the triangle corner areas - those are spots where one side needs to kind of stop in place on one side but continue along the other rail sort of like a pivoting action. Surfacing commands don't know how to do that kind of "stop and pivot" at some internal spot, they try to just build one even surface between the rails or guide curves, and they want to march in steps along the rails all the time instead of doing any stopping. So if you need that kind of pivoting you have to split things up into some smaller curves and do the pieces around the pivot separately.

If you have a section where there is a longer evenly matching sequence without any internal pivots then you can do sections like that all in one Network or Sweep.

Hope this helps!

- Michael