How to do Flip matrix in multiple lists? or Open Brep to Surface?

Hi all,
I am beginner of grasshopper, and trying to make some spiral shape with multiple curves.
For now, I struggled with drawing curves on the other way through spiral.

What I want to do is, drawing curves like blue sketch…
Flip matrix works if input is only one curve, but it doesn’t work when multiple curves.
So I tried divide surface after loft, but the result of loft was open Brep.

Can you help me?
Thanks. (24.6 KB)

Get the flip last matrix component from tree sloth.

1 Like

You can also use PathMapper.
{A;B}(i) to {A;i}(B) (28.3 KB)

1 Like

Thank you! This is amazing component!

Thank you! I haven’t used this before. Great solution!