I have a similar issue with creating 3-d routed pipes (or wires). I tried to set a network of 3d loci, first spotted on the working plane, then (laboriously) moving the selected ones in 3-d to desired elevations. Then, ideally, a series of lines and nurbs arcs should be able to snap to the loci now in 3-space.
This does not work. The nurbs arcs remain on the plane and do not snap to the loci (I was using both center and endpoints, and 3 points, to create).
I tried this using Nurbs curve tool, it sort of works, but not with nice specified radii.
Is there a way to draw a nurbs *line* between 3-d loci in space?