I made this definition that maybe someone else might find helpful, or might help me improve it. I have only tested it with a spherical surface.
It does the following: Given a surface constructed by triangulated bars, it calculates the minimum radius required for each node so that the bars don't overlap before they reach the node (this can be displayed as the exact radius, or rounded to 3 types of nodes). It also displays as red the nodes in which the bars connected to it are too convex and incorrectly intersects the disc area part of the node (this can be fixed by increasing the node height). I'm not sure if it will work for concave nodes, haven't tried it. The cluster at the left just generates some geometry for a preview, it can be deleted. It works by trigonometry, not by intersections, so its very possible i did something wrong somewhere, but it sort of looks like it works. http://grasshopper3d.googlegroups.com/web/nodesfrombars.jpg http://grasshopper3d.googlegroups.com/web/nodesfrombars.gh
