Align all curve normals

I have been trying to get all of these vectors to follow the surface but somehow they flip. does anyone have an idea to solve this.
All the vector need to be in one direction.


Could you please attach your GH file with internalized geometry ?

Hi @magicteddy, thanks for offering your help.
I was actually able to solve my problem yesterday, with a similar topic on the old Grasshopper forum. I have internalized my file and uploaded it to this forum. For everyone’s reference…

Aline all (17.4 KB)

Here’s another way…

Aline all (15.8 KB)


Given the opportunity: If the Crvs are due to some Surf/Face divisions (classic/math driven/random) the bulletproof solution (any valid Topology etc etc) is to use IsoUVCurv Tangents. That way you don’t need Dot/Cross Products comparisons et al.

Anyway … see attached that deals with BrepFace Lists (but it’s pure C# so the usage may be limited for you). (185.9 KB)