Grasshopper
triangular mesh frame optimization
Hello. I'm an architecture student with little experience who just graduated from school. But I decided to give a shot at a small scale real life competition. I intend to use triangular mesh frame to support the windows and the whole building. The best example to illustrate this is the Blob in Eindhoven (see attached image), although I don't intend to use a blobby form.
But the main question here is the optimization of the structural mesh frame. It is easy to make a mesh in rhino for any given surface by simply typing "mesh", but first the individual shape and size of each mesh face will vary, and second the connection vertex between different faces are all different too. As a result, it will be incredibly hard and costly to build in real life.
So, as many others have already did in this forum, I'm wondering ways of optimizing mesh by limiting the shape and size of each face. And also can someone shed me some light on how does real life "meshing" work (examples of connections and construction methods)?
From searching this forum, I found lots of similar threads. Many of them ask how to cover a curvy surface using identical equilateral triangles. The answer seems that a smooth covering is impossible as long as the surface isn't developpable, and only approximations can be made using kangaroo.
Daniel had some good scripts regarding this http://www.grasshopper3d.com/forum/topics/triangulation-scrip-with and
http://www.grasshopper3d.com/forum/topics/folded-plane-subdivided-i...
And I also encountered a script that can approximate a curved surface with limited set of triangles, but cannot find it anymore.
But all of the scripts above have their problems in real-life fabrication, as the first script has triangles approximately equilateral but not really so, and the second script has to change the border of the surface. I'm just wondering how did people do this kind of thing in real life, like the Blob in Eindhoven or Ghery's abu dhabi guggenheim museum's long transparent tubes. Did they just simply prefabricated everything or did they have everything optimized to the max? How did they do that?
Sorry for this long and demanding question lol. But any direction of research is appreciated. :) Thanks!
Jonah Hawk
There are only three volumetric forms that have identical equilateral triangles. Ask Plato.
The fact is that every triangulated surface you see in architecture has at least two different sized triangles. Geodesic domes are the simplest example of this. Most of the large geodesic domes you see have six different edge lengths. This is for a sphere, where the curvature is uniform across the surface. When you introduce compound curved surfaces, the number of unique components goes up.
You can use Kangaroo and other tools to try and optimize a triangulated mesh over a surface. There are various grasshopper definitions out there that will continually iterate over the mesh, moving vertices until all edge lengths are as close as possible. But this does not guarantee that the triangle panels will have the same angles/form.
often the panels are not exactly the same size but they are close. So the panels are manufactured the same size and shape but the difference is made up in the glazing, frame or mounting method. The gaps vary but the panels are identical.
You could build a definition to sort and group them according to their deviation from a norm. For example: Stack all the panels with the same vertex (A) at 0,0. Align a single edge, (A-B). Then measure the deviation of points B and C and measure the angles, ABC, BCA andCAB. derive some sort of tolerance that groups similar panels together.
There are examples of this out there.
Mar 6, 2015
peter fotiadis
Well... let's speak a bit having the big picture in mind - not just panel aesthetics.
1. I have several defs that do a variety of similar things but they are ALL in C# and thus they don't use components (other than Kangaroo - if required). Anyway notify if you want some taste of them (but they are a bit "chaotic" : too many parameters etc etc ...). Warning: Almost all are written with MCAD apps in mind: GH is used SOLELY as a graphical editor/topology solver and just makes the simplest instance definitions possible in order to send them (via STEP) to some MCAD (Frank G uses CATIA/Digital Project as you may probably know, CATIA is my favorite toy as well) for actually designing the components and composing the whole.
2. "Equality" in modules (panels/glass/lexan) it's not an issue (other than aesthetics). I mean cost wise since modules are prepared via CNC these days. I wouldn't suggest to waste your time with "equality" puzzles and completely ignoring the big picture (real-life) that is FAR and AWAY from aesthetics. I mean: assume that I of someone else or Daniel can "equalize" things (up to a point): Is this sufficient for designing a similar real-life solution? In plain English: don't get occupied by the tree and ignore the forest.
3. As regards the frame in most of cases some MERO type of modular system is used: either a "flat" dome-like arrangement or a classic spaceframe or a hybrid system [push: tubes, pull: cables]. Hybrids are the most WOW (and costly) for obvious reasons. When properly done (and combined with a planar glazing system) THIS is the star of the show.
4. As regards the skin we use either "hinged" custom stuctural/semi structural aluminum extrusions (they can adapt to different dihedrals up to a point) or classic custom planar SS16L systems that also can adapt to dihedrals. A custom planar glazing solution is hideously expensive, mind (say: 1K Euros per m2).
5. Smart Glass tech (changes light transmission properties under the application of voltage) is gradually penetrating the market especially in future bespoke designs.
So in a nutshell: these are "pro" territory - if I may use the term, thus I don't expect to find ANY similar "turn-key" solution in the very same sense that you can't find a tensile membrane turn-key solution.
Meaning that practices that can do it ... er ... they keep the cookies for themselves.
Mar 7, 2015