Grasshopper in the wind

Just a quick update on the parametrics of the structure of my walkway/lookout.

Although a simple triangular truss is all that is necessary here I've been working to add an element of movement in the static structural element.  This is based on a offset of the bottom chord of the truss so that the sections throughout are no longer static equilateral triangles.  The sections triangles in my current scheme are continuously variable, as is the density of the triangulation.  Sure, this would be possible to model in Rhino, but that would be a huge pain in the ass, so this is all in Grasshopper, which of course gives me the chance to play with the various spacings, offsets and shifts, of which there are many in this scheme.  The downside to this whole idea is that the equilateral triangle is the default section of a three-dimensional truss for a reason: its the strongest.  By skewing that triangle I'm reducing the overall strength of the truss.  I've made up for this by tightening up the triangulation density.  I'm fairly happy with the result, even though the structure is the static element of the design, it gives the impression of twisting back and forth along the length of the walkway.  I've exaggerated this by extending the vertical elements of the triangulation and linking them with cables.  Eventually these extensions will also support the railing (actually I'd be happier if the top link could BE the railing but I think it is too far from the edge in many places).

Final note: The images below show only the structure, no boards (tread surface), no overhead membrane and no active armatures (yet).  That stuff's pretty much done too, but I haven't put it all in grasshopper yet.

Skewed truss section, unusual and intentional

Front Elevation showing the variable triangulation density

Plan

Thanks to the beauty of parametric design I can say that this is not necessarily the final length, inclination, shape or platform size.  All those parameters will likely change a bit as I add this model to my site.

...and the obligatory/somewhat cliche, overly complicated seeming Grasshopper screenshot (that likely doesn't impress anyone with a passing familiarity with grasshopper...) (and yes, its a bit messy)

Next up, add the tread boards to this definition (not too hard) then add and link the active armatures (harder...)