CREATING 3D NETS IN GRASSHOPPER

I am a student in Monterrey TEC, in Mexico. I came upon this
blog looking for some tutorials of grasshopper and thinking maybe you can help
me with a net I want to design. Basically what it is like a 2d grid from
grasshopper but in 3d, fully controllable of course. I want to do something
like the image in this web
site:http://news.cnet.com/Photos-Weaving-high-tech-fabrics-of-the-future—page-12/2009-1008_3-5667576-12.html

I figured that connecting points and lines kind of works
(point and line input AB command) but the line length changes when I move a
point. What I want to be able to do is to move a point and drag others but keep
the line segments constant, just as a real net.