Hexachiral structure on double curvature surface

Hi everybody,

I'm quite new to grasshopper but I have to face a problem which, I think, it's not so easy to solve:

Creating an hexachiral structure that follows a double curvature surface.

As hexachiral structure I mean something like these in the above image

(note: the cylinders are called "nodes" and the linking surfaces between them are called "ligaments")

I easily managed to design a definition for planar surfaces by using Tangent Lines (Internal) between circles created on an hexagonal grid and the extruding it all.

Anyway it seems to be impossible to find tha internal tangent lines between two non planar circles, so my firs attempt was to get the endpoints of the tangent lines in the planar surface and then use the function "orient" between planes on the planar surface and corrisponding planes on the double curv surface.

This seemed to work, but only as long as the relative distance between the nodes in the planar surface reproduced exactly that of the nodes on the double curv surface.

I tryed different solutions (projecting the center points of the dc nodes on a plane, remapping UV's of the "dc" on a planar surface...) to obtain a planar surface respecting the topology of the double curvature one, but none worked well.

I think that there are possibly two solutions for my problem, but unluckly I don't know how to realize either:

- first possible solution involves unwrapping the dc surface, thus finding the tangent lines between the planar unwrapped nodes

- second possible solution is to find a way to directly create the ligaments between the cylinders on the dc surface.

I attach my attempt and a sample file with the planar solution and a double curvature surface.

Thanks to everybody in advance for your help!

Ross