Tensile Membrane from closed polyline

Replies to This Discussion

Permalink Reply by Kibito Tato on September 10, 2014 at 10:47am

nice

Permalink Reply by loc nguyen on September 26, 2014 at 11:26pm

Hi Selini,

I really appreciate your help. :)  

By the way, If I want to adjust the curve of boundary as mark in green (attached file), what should i do?

I tried to change the value of {rest length} but it doesn't work. 

Thanks a lot!

Loc.

Attachments:

• 9-27-2014 12-01-34 PM.jpg, 78 KB

Permalink Reply by peter fotiadis on September 28, 2014 at 4:34am

You can work on this as well (requires a lot of C# scripts in order to work as in real-life: masts, cables, multiple boundaries etc etc).

Tip: always separate valence2 lines from boundary

Tip: Test the MinSurf attached def as well (i.e. Starling in use) : for preparing trimmed breps for Kangaroo and/or outlining minimal breps (as "standalone"). Pay attention to the fact that GH can't internalize data (use Rhino file if this is the case)

best, Peter

Attachments:

• Tens_from_polyline_v3.gh, 43 KB
• MinSurf_Starling_Peter_v4.gh, 503 KB
• MinSurf_Starling_Peter_v4.3dm, 813 KB

Permalink Reply by Selini Serefoglou on September 28, 2014 at 9:47am

Thank you so much! I will work on it! (Although I'm not familiar with C# yet)
What do you mean GH can't internalise data? I do it all the time..
I made this for a project in the university but the professor told me that in order for the fabric material to work as a tensile, I need to have 4 corners, and the corners need to be A high- B low- C high- D low to create the necessary tension. I probably shouldn't call the previously uploaded one tensile.. the result I ended up with now is in the attachment!

Attachments:

• stegastra biblio8hkhs 3.3dm, 2.4 MB
• stegastra biblio8hkhs 3b.gh, 28 KB

Permalink Reply by Selini Serefoglou on September 28, 2014 at 10:54am

I'm missing some plugins I think to open v4. As for v3 that's what my teacher explained! but we needed 4 corners. here's to v3 :P

Attachments:

• Tens_from_polyline_v3 mazochistic answer.gh, 20 KB

Permalink Reply by peter fotiadis on September 29, 2014 at 12:07am

Hi Selini

Good(?) news: Have a look on these as well

http://www.grasshopper3d.com/forum/topics/tensile-membranes-test2

http://www.grasshopper3d.com/forum/topics/tensile-membranes-test

(Note: Images included may NOT load due to that GH internalize bug thing).

Bad news: I'll upload soon (in a separate thread : tensile-membranes-test3) a far more realistic (and complex) case where a variety of C# things do all the input (a variable grid 300*200m + masts + cables + dogs + cats) and Kangaroo does all the rest (Plan A) or Starling does all the rest (Plan B).

Ugly news: Neither GH nor Rhino can handle properly components that are critical in membrane design - I mean things that we use in that ugly bit called real-life (and in shop level of drawings called final study level). 

PS: stegastra bibliothikis ??? I like that (I'm Greek).

may the Force (dark option) be with you

best, Peter

Permalink Reply by peter fotiadis on September 29, 2014 at 4:06am

PS: Sadistic A1: you forgot the cables (smooth + sadisticQ + masochisticA).

PS: Sadistic Q2: what happens if you add a hole or some of them (normal or inverse cone(s)) - wait for the tensile-membranes-test3 .

PS: Tell your professor that the corner (anchor) topology (as regards Z) thing is more complex that he think (Has he designed anything in real-life?) - play with the 10 pts polyline provided (say 2 or more consecutive points with "about" the same Z as opposed the classic approach: one up there, the next down there : convex/concave membrane "subdomains" etc etc).

Permalink Reply by Selini Serefoglou on September 30, 2014 at 5:52am

My teacher rocks :P He has designed irl, what i sent before is still on the formfinding stage, we'll see about the constructional part later!

Permalink Reply by peter fotiadis on September 30, 2014 at 7:15am

if (teacher != rockNrolla){

redoStegastraBibliothikis(bool untilOK, int manyTimes, double forEver);

}

else {

redoStegastraBibliothikis(bool untilBetter, int fewerTimes, double whyNot);

}

PS: put some Z diff more - as it is it stresses things unnecessarily and looks a bit unadventurous.

Permalink Reply by Selini Serefoglou on September 30, 2014 at 5:55am

I think the problem is that your second green point makes it a concave polygon, which makes it fold on itself. You probably need a convex one to work properly 100%.

http://en.wikipedia.org/wiki/Convex_and_concave_polygons