Surface From Network of Curves - Help!

Hello All,
I’ve been unable to create the surface that I need from these curves. The model is a 2 meter long towing tank sailboat hull. The surface will not be fair (and this is OK), as the lines are taken from the actual physical model (measured with a CMM). I was able to use Surface From Network of Curves for the main hull, but I cannot get the bow section to cooperate. I am OK with having multiple surfaces and then joining them. Ideally I get the entire hull (including the bow (forward) section in one surface, but its not mandatory. This model will be used for CFD analysis in Orca3D.
The surface needs to be as faithful as possible to the curves. I cannot change them. If I am within .5 mm along every curve length then I am in tolerance.
I have tried using various combinations of open curves and closed curves (just by joining or breaking them), and I choose the curves individually, but no matter what or how I choose them the command gives no result returned. All curves intersect one another (that is, they touch wherever they cross). All curves are Degree 3, with the directions apparently similar (though I don’t know if that makes a difference with this method). I have also tried using just some of the curves, even down to just picking 3 curves in each direction. More is better for fidelity to the desired shape, but I don’t know if there is a maximum number of curves allowable. Any help would be greatly appreciated.
Many thanks!!

Mini CFD Model - Final V1 copy.3dm (5.1 MB)

By splitting the horizontal curves, I was able to use networksrf up to the last part…

Mini CFD Model - Final V1 copy_networksrf.3dm (803.4 KB)

From there, used networksrf to patch the left and right sides of the main front.
I used split edge of the surface edge to get the open curves I need for the left and right front side, to get tangency.
(I was hoping the networksrf would
go down to the bottom but ended up doing network srf again… at the end…)

Thanks Toshiaki. It was really helpful that you explained how you went about it - and a bonus that you gave me back the part! I have duplicated your method and now I understand a little better about what networksurf wants to use. I’m still a little unclear, but I will do some more components to try to make some sense of when it wants open and when it wants closed curves.
Your input is very much appreciated!


Great I can help. Maybe someone out there can align the curves to do it
in one shot… I also need more learning to do… watching videos and using this forum :wink: