Membrane by Kangaroo component in Grasshopper

Replies to This Discussion

Permalink Reply by peter fotiadis on February 22, 2017 at 9:33am

If the anchors are not mesh vertices you should use "special" additional springs: connect appropriate (say the prox one with regard a given anchor point) mesh naked vertices to your anchors (do that using separate springs for these since their stiffness has nothing to do with the mesh edges stiffness) in order to instruct the engine to "relate" these vertices with the anchors via these springs.

Is that all? NO: in real-life (tensile membranes) we always apply forces per pairs of cables (per mounting plate) that are inside a pocket running "along" the perimeter > meaning that you should separate the mesh edges in the naked ones and the rest.

So you need 2 kinds of springs for the mesh and 1 for the anchor cables.

Permalink Reply by peter fotiadis on February 22, 2017 at 10:28am

PS: Forgot to mention the obvious: your anchor points should differ in Z (say: odd points up, even down) in order to avoid a flattish relaxed mesh that has no meaning (at least as a tensile membrane). If the thing is big an inverse/normal cone (or many) could make things easier.

Like:

In rare occasions we deviate from the one up the next down anchor rule ... but that's for smallish membrane pieces (not to mention that in the long term is BAD engineering - membrane fails sooner or later).

Permalink Reply by Tran Khanh Lam on March 20, 2017 at 7:42pm

Many thanks to your reply. It's so detailed. I'll try to do base on your methods.

Permalink Reply by peter fotiadis on March 21, 2017 at 1:34am

On the other hand:

IF you have plans to do membranes in real-life I would strongly suggest to start contacting specialized makers (like BirdAir) since it's impossible to do that type of stuff without a close collaboration with them. Keep in mind that a membrane is 1% the "tissue" and 99% the nuts and bits that keep the tissue properly in place. In order to design bespoke nuts and bits you'll need a decent feature driven solid MCAD app (from CATIA/NX to Solidworks) - Rhino is NOT suitable for that type of work by any means.

The Catch 22 is that these specialized fellas they don't pay any attention to you if they don't know you ... but in order to know you ... blah, blah. 

Permalink Reply by Tran Khanh Lam on March 21, 2017 at 2:58am

wow, your informations are so helpful to me. They were open my mind in this area. Surely, you are a master in this major. Honestly, I am really thankfull for your explaination. Nice to meet you, sir Peter Fotiadis.

Permalink Reply by Tran Khanh Lam on March 21, 2017 at 4:36am

These are great projects. Could you share grasshoper or rhino files with me, please? It 's so good to learn from you. Thank you very much.

Permalink Reply by peter fotiadis on March 21, 2017 at 7:25am

Er... well... no problem ... but there's 2 things that you should consider:

1. Call me with any name you want except Sir (Peter/Lord of Darkness is fine, also try: King of SardineLand).

2. My solutions are carried over solely via code even for tasks related with K2 (for a vast variety of reasons mostly related with "communications" to/from other CAD apps used in a real-life BIM driven AEC pipeline [where GH plays a small role]).

If 2 is OK with you, drop a word.

Permalink Reply by Tran Khanh Lam on March 21, 2017 at 9:32pm

It's OK, Peter. I'm glad to study whoever like you. I guess you also work in architecture, right? I am an architect and I research in BIM and code in Grasshopper. Nice to study from you. You can contact me via my email : rinsan37@gmail.com. Thanks.