designed in maya, blender, pepakura, rhino3d
To create this shape I wrote a program which ran in the 3d modeling program maya. The program took a base object, in this case a hexagonal-cross-section tube, and made many copies of it. The copies were in a hierarchy where each copy was in the local coordinate space of the previous copy. The copy also inherited the transform of one of the previous copies. The result was that rotation, location and scale of the first set of copies controlled the overall shape of the branching structure. With this tool I designed this shape. The final base shape was unwrapped in pepakura. This unwrapping was copied and scaled in rhino3d and finally those parts were laser-cut and assembled by hand with glue.
This instructable describes the process in more detail: http://www.instructables.com/id/Branching-Fractal-Shapes/