Create triangular surfaces between two unparalleled lines

Hi there,

I am working on a project with a 3D curved surface composed of flat triangles. I did the first trial which was ok as below:


However, when I built for the real project, it is like this:
looks like only the first two are right. FT-09 001 is the right one. 002 is the issue.
Appreicated so much if anyone can have a look and guide:) xxoo

FT09-002.gh (18.9 KB) FT-09-001.3dm (45.6 KB) FT09-001.gh (18.5 KB) FT-09-002.3dm (198.8 KB)