Hello
I don’t understand why I’m not getting ribbons built on a convex surface, why not enough points to build a curve?
you are getting that error because the Subdivide Surface component is creating 80+1 branches of 6+1 points most of which are Nulls, so when that list -containing Nulls- goes into the Interpolate component it is not able to create a curve out of lists with Null points: this happens because the Subdivide Surface component (as for most of surface-dedicated components) operates on untrimmed surfaces
maybe Iso Curve better suits your needs?
this Geometry is not internalized / not present on the Rhino file
(I suggest, instead of attaching Rhino + GH file, to right click on any GH Parameter containing something you have referenced to Rhino and chose Internalise Data: this way Geometry is stored inside your GH file, and you won’t need to attach any Rhino file)
