Generate 3D shape based on drawn planar flexible frame with applied stretched material

Hello everybody!

I am looking for some way in grasshopper (probably plug-in) that can help me generate 3D shape obtained by designing a planar frame made of flexible (but rigid) material and a stretched membrane over it.

I attached the photo to make it easier to understand.

We intend to create this kind of forms in real, but before that we need to simulate the shape.

Basically the objective is to be able to draw the planar shape and grasshopper should be able to simulate the 3D outcome for it...

Probably even if you don't know how to do it, maybe u can recommend some related plug-ins.

Thank you all very much!

Olga

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Replies to This Discussion

Permalink Reply by Anders Holden Deleuran on February 16, 2016 at 6:36am

I would look into Kangaroo for this. I've previously modelled something similar (electro-active polymer hybrids, see this video for an example) using the Nucleus physics engine in Maya, but I don't see any reason why you couldn't do the same with Kangaroo (1 or 2). Hope that helps.

Edit: Paper here.

Permalink Reply by Olga on February 16, 2016 at 6:47am

In fact we are planning to work with electro-active polymers and this we need for simulation. I'm trying to learn Grasshopper for it, as it seems the right tool for the purpose. I will try now to work with Kangaroo! Is it very complex algorhytm, cause I'm a begginer in Grasshopper :D

The simulation that you have attached is the one made by you in Maya?

Thank you!

Permalink Reply by Anders Holden Deleuran on February 16, 2016 at 6:55am

Well there you go then :) Yes the animation is the one from Maya, but the same hybrid behaviour should be doable with Kangaroo. Basically: You want to model a mesh representing the frame and a mesh representing the membrane/polymer. For the frame mesh you want to create Kangaroo goals/forces for bending resistance and goals/forces that maintain mesh edge lengths. For the membrane/polymer you just want to make goals/forces which minimize the mesh edge lengths. At least in principle. Maybe start out by searching for how to model minimal surfaces using Kangaroo (many threads on that), then look into modelling meshes which have bending resistance (so shells basically). And once you're comfortable with that, try to combine the two. Start out simple, then slowly ramp up complexity.

Permalink Reply by Olga on February 16, 2016 at 6:58am

Thank you very much! I will start as you suggested!

I read a bit of paper, it's very interesting and seems to be exactly to the topic :)

Permalink Reply by peter fotiadis on February 16, 2016 at 7:29am

Well ... this is rather easily achievable via K1/2 (I prefer K1 mind - K for Kangaroo) but the big thing is that you should think ways to hold the "central" bulge in place (or put it differently: ways to control the desired bulge "shape") unless:

you replace the "elastic" membrane (BTW: you mean tensile??) with a geodetic dome (with or without W depth). BTW: Birdair does a transparent membrane.

you carefully balance urinary forces (anti-gravity so to speak) VS K spring constrains.

For instance the attached images (shown cone [classic/unversed] or no cone) are related with a "quite" similar case (well .. almost since the anchor points are discreet and not all the Valence 1 mesh vertices ("along" a perimeter truss - as in your case), plus there's masts; but that's entirely trivial to address).

Note: all the above may appear easy/entry level ... but ... er ... hmm ... I wouldn't recommend attempting them AT ALL without a certain GH/K experience.

Permalink Reply by Anders Holden Deleuran on February 16, 2016 at 7:37am

Way to information-overload AND miss the overall modelling challenge there Peter..

Permalink Reply by peter fotiadis on February 16, 2016 at 7:49am

What modelling challenge? (an "other" modelling challenge, that is) It's the very same thing if you replace specific anchor points with all the valence 1 points and make some "wavy" perimeter truss for the main Load Bearing System or a "wavy" tube like frame (not that trivial to do in real-life).

BTW: the masts are waaaay simpler solution than a real-life wavy truss.

But maybe you are right: I always evaluate things having AEC stuff in mind (of a certain scale).

Maybe I'll post later something on that matter.

Permalink Reply by Anders Holden Deleuran on February 16, 2016 at 7:57am

This one: https://en.wikipedia.org/wiki/Electroactive_polymers

Permalink Reply by peter fotiadis on February 16, 2016 at 2:55pm

Hmm...

Anyway - given the opportunity - IF we replace polymers with some sort of tensile membrane and IF this has remotely some sort of relation with AEC matters > this draft outlines the way to do it.

Using Starling for the polyline > mesh task.

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