Grasshopper

algorithmic modeling for Rhino

Catenary Surface with attracting points in the middle of plane?

I need to make a surface that hovers over a landscape and then reacts by following individual points int he middle of the surface and contacting them at the ground level. How do I do this? My previous attempt have been disappointingly fruitless.

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Replies to This Discussion

Permalink Reply by Alexandra Foster on March 29, 2016 at 1:17pm

Man, you are a life saver.  I'm a total greenbee at all of this. I just want to make something cool and understand how it works.  You are resurrecting my composted motivation. Ahhh youre the best.

Because I am such a beginner... i'll just do a quick paraphrase to make sure I'm up to speed? or sorta jogging along at a reasonable pace...

1. When you say "holes" you literally mean perforations in the surface... right? And these are coded as "loops"

2. So for each hole, each is pushed around by the unary z (or I suppose any force...?) and is locked up to some extent by an anchor (which can be stretchy).

3. What is the max span? you mean the max distance between points? sorry... lots of dumb questions here.

4. Noted.

5. Code bites hard. I'm pretty sure. You are too awesome. I can be a happy bunny... just how do you make this code?

6. No worries about real life.  This is completely digital.  It could be an art project... maybe a visual social network... idk... doesn't need to be built... just visualized.

7. You are my hero.  I'm working through it all now.  Maybe if I get super smart super fast I will process all of this and be a kangaroo whiz.  One can dream... At any rate thanks for your patience and your competence.  Totally the coolest.

Permalink Reply by peter fotiadis on March 30, 2016 at 12:00am

Well..

1. Holes are indeed perforations in a surface. That said a surface without holes (or trim on the outer loop) is a surface whilst the thing with all that (I.e. the trimming stuff) is called Brep (Boundary Representation]. Thus a Brep is 2 things: the underlying "guide" surface and "regions" that do the massacre.

2. As delivered and if you chose the equivalent boolean some Delaunay faces are removed from the mesh IF their center (the projection in an automated made "min"  plane) is contained (is inside) to a giiven hole. Now ... the anchors ARE not the white points ... they are their projections on the terrain (the red ones). Thus proper springs "pull" the white points towards the red ones.   

3. Max span is a term used in that ugly part of life (the real-life) and indeed refers to some distance between mount points. For instance the Golden Gate has a max span of 1280 m. Span means money and big span ... er ... means lot's of money (even on trusses, considerably less so in tensile membranes).

5. Coding is like riding properly a proper Ducati (avoid the 999 at any cost): easy provided that you can ride it. Lethal in any other situation. But the good (or bad) news are that girls don't ride that type of bikes.

6. This makes me entirely off-topic > Oops > anything that I do/think  points directly or indirectly (in most of the threads in this Forum) towards real-life AEC thingies. I never (ever) think within an Academic/Theoretical framework. BTW: Avoid social networks > or say hello to Skynet (or lobotomy).

7. You are very kind.

Permalink Reply by peter fotiadis on March 30, 2016 at 12:36am

Forgot to mention:

IF the terrain is "steep" (say kinda "sides" on Grand Canyon and the likes) Delaunay DOESN'T work > you'll need a proper Ball Pivot thingy to do the mesh. Or you can approach this as a graph (using proximity and the likes) but that requires code. in order to control what "faces" go to Daniel's stuff (not to mention the structural integrity of the whole combo). This is especially true if you need only triangles for defining, say, mini tensile membranes (a bad policy used only for small sized membranes - other wise you'll need saddle topology on these).

Permalink Reply by peter fotiadis on March 30, 2016 at 11:56am

BTW: Here's Plan B (won the first prize for the most unrealistically unreal stuff in a recent competition in Planet Utopia, no kidding).

Using a variety of things (mostly naive) you can do mini triangular tensile membranes (that's LOL and wrong by definition) and be an unhappy bunny (life sucks).

Moral: life sucks

best, Lord of Darkness (Prince of SardineLand)

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Permalink Reply by peter fotiadis on March 31, 2016 at 2:29am

BTW: First get the gist of that:

https://www.youtube.com/watch?v=9puxoJ1f6YU

and then ... maybe ... you can understand that the big thingy in the parametric thingy is ...er ... to bypass the parametric thingy (I.e. control things in collections on a per individual item basis: applies in 66,66 cases in this humble V1A).

Wonder if I should post the V2 (totally politically incorrect, mind).

he he.

Permalink Reply by Alexandra Foster on March 31, 2016 at 7:50pm

So.... if you haven't lost all interest yet, or something else hasn't caught your fancy, do you think you could give this a look?

I've got a few questions on there about the coding and the kangaroo.

Thanks so much!

**Huge Sean fan... but in greek??

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Permalink Reply by peter fotiadis on April 1, 2016 at 4:25am

Well ... this is unacceptable > after the freaky things that I've provided to you ... you answer with THAT? How had the mighty fallen etc etc.

1. For reasons of political correctness I can't explicitly write here my opinion ... but I guess that this is rather sufficient (red for anger):

2. Assuming that you want that type of stuff (an inflated thingy having the naked pts as Anchors and respecting the inner Loops [circles]) I did this, this and that:

Moral: buy a proper Ducati > ride it at WOT > life's short. 

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Permalink Reply by Alexandra Foster on April 1, 2016 at 9:22pm

Thank you! Disappointing questions, yes. I'm ashamed, but you answered them beautifully. 

But don't worry- all of the other glorious stuff you put (except that pseudo-structure... which is cool, but maybe if the project goes into another supr hypothetical direction) is totally relevant and I can't wit to work it in- god, coding is so powerful. I've got to learn this.

But one lasssstttt question-  how can I make those holes by the people slightly more circular? 

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Permalink Reply by peter fotiadis on April 1, 2016 at 11:26pm

Well ...First things first:

1. What bike you ride? This is the most critical test. Plus: who penned the immortal 916? (And who - totally untalented - did the awful 999?).

2. The approach that you follow is a rabbit hole > abandon ship. Reason? Well ... if you want to "trace" more "accurately" the inner circles you must use a very refined mesh > meaning a zillion faces > a gazillion edges > WHY? (you tell me).

3. Additionally ... IF a given circle is proximal to the outer Loop (the "perimeter") you need at last 3 "layers" of faces in order to achieve the inflated "multi vault" goal ... otherwise that "portion" stays on the ground > thanks but no thanks.

4. Anchor policy: sucks for more than obvious reasons. See V2 ... where all the "outer" vertices are used > so what?

5. A vault may appear "interesting" but in real-life costs an arm and a leg (and is Kitsch as well). A tensile membrane (250-350 Euro/m2 for a large scale thingy) is the way to go. Even if this is Academic it should NOT mean that is ... well ... Academic.

6. As the greatest ever said: Less is More.

I hear you: what about a tensegrity thingy? (Coolest and "cheapest" truss known to man).

Moral: control + alt + defeat. 

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Permalink Reply by peter fotiadis on April 2, 2016 at 1:13am

BTW: What about Plan Z?

Note: in order to receive further assistance you MUST answer correctly the questions related with the 916/999 thingies.

Moral: No Mercy

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Permalink Reply by peter fotiadis on April 2, 2016 at 2:40am

BTW: What about PlanZ plus?

Tip: The pink thingy is highly recommended (Lord doesn't like Viruses).

Note: Load R file first.

Moral: Go for the pig > eliminate Viruses.

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Permalink Reply by Alexandra Foster on April 2, 2016 at 3:31am

Thanks again, Peter. Where do you pull this stuff from?

1. I ride a Schwinn. I assume those numbers are model numbers?  After a brief scan of sportsbike images, I think the Kawasaki bikes have more expressive lines.  But, meh, I still pedal to get around.

2. So what if I make a pseudo-refined mesh- not a bajillion points, just something that would give me like ten points, instead of four...?

3. three layers of faces?? What do you mean... like I should just split the mesh more?

4. yah, icky. :P.  Perhaps not academic... maybe abstractly whimsical? Tensile is cool too--- sky cables are super fine, I'm sort of working with a blank check here.

5***. SERGIO ROBBIANO.  Just found it. and Pierre Terblanche.

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