# A better way to build this cable net?

Going cross eyed trying to figure out the logic on this, I know it’s probably simple. I have this cable net below, supporting a grid shell. It’s just hovering right now but I’m going to add the kingposts next.

I created it sorta manually by duplicating components but for this assignment it has to be adaptable to any number of ribs and any form. Meaning I need to trim this monster down and make it truly parametric. I’m guessing a Series and List Length comes into play, with clever list management but I haven’t quite added up the solution yet. Would appreciate a shove in the right direction.

Attaching a simplified GH with internalized curves. I’m using Intersect Curves from Paneling Tools but that prob isn’t necessary, it’s just what I started with.

taiuan cable net1.gh (357.8 KB)

Is that statement meant to sound humble? Because it always strikes me as naive and presumptuous.

How are the curves generated? Are they catenaries? Is there a surface that controls their shape?

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If I get it right, you could use Relative Item for this.

taiuan cable net1_re.gh (351.3 KB)

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Haha, sorry. I have so many plugins it’s absurd. I forget what I am grabbing from via the search bar.

To answer your question, naïve sure, but not humble so much as self deprecating. I’m studying parametric design at a university now but I’m mostly self taught, I have blind spots and bad habits so I am embarrassed about asking questions I perceive might be simple, that I should already understand having worked with Grasshopper for years.

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That’s perfect, thank you. I haven’t used relatives before, very handy.

taiuan cable net1_reV2.gh (353.8 KB)

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Yeah, but usually when I hear that phrase on this forum, the issue is not as simple as the wording implies.

I could use fewer components with Entwine but this is an expedient way to have one set of beams above the curves and the other set below.

taiuan cable net_2021Feb6a.gh (343.4 KB)

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Thanks, yes from a surface, remeshed with Kangaroo.

Thank you! I was able to adapt that to the target form for the class, a “Richmond Surface.”

So this surface is a big pain in my ass, as it was intended to be. With the mix of curvature directions, the net is clipping through the surface, also useless in some areas but imma not worry about that yet. I’d like to explode the net into segments, test each for Curve Surface Intersection and Cull. Do you know of a component for testing that? I was trying to adapt Curve | Surface but it seems like a convoluted journey, working from intersection points to true/false results in the same tree.

It gets better or worse depending on the Net Offset.

For reference btw, this me trying to recreate and adapt the building systems used on the Taiyuan Domes. Still a long way off obviously, I’m just trying to approximate the cable nets that support the grid right now.

richmond cable net1.gh (1017.4 KB)

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it’s probably simple.

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Not the solution I was hoping for, a Band-Aid but I targeted the problem children using a Point List and Cull Indexed them. I’ll get back to this curve/surface intersection thing another day. I found a promising plugin on Food 4 Rhino but the zip is reading as invalid.