14 Feb


14. February 2011 by George Profenza

Lately I got interested in 3D geometry again. In the past I played with 3D packages like 3dsmax, blender and Cinema 4D, managed to code a few structures here an there using either plain OpenGL, either 3D APIs like three.js, Away3D, Papervision3D, etc.

Now I wanted to try to make physical models, instead of just having them on a screen, in this abstract/limitless world. I peaked a bit at the process of designing models for the real world and thinking/doing 3D without a computer…

Last week I went for a 2 day workshop on Generative Design for Robotic Manufacture. The goal was to learn how to take paper folded prototypes into Rhino, parameterize them using Grasshopper, do verlet physics simulations using Kangaroo and hopefully use Lobster IK to simulate the robot movements too. This workflow would help tweak prototypes before they could finally be produced by RoboFold robots.

Ok, I’ll admit is sounds a bit much, but let me explain what’s all this about: Rhino is a pretty interesting CAD software, used mostly in architecture, product design, jewelry and other manufacturing practices. The first thing that hit me when I started using it, was the fact that the interface, although packed with features, was very logically organized. It provides multiple draw modes which makes it easy to get precise models. It has an AutoCAD like command line interface which makes repetitive tasks faster and the first thing you see when you open up Rhino is a dialog asking for real world measures. Where 3dsmax/blender/C4D seem geared more towards animation, game design and visualization (although product design isn’t out of the question), Rhino is clearly designing for making objects for the real world.

Sounds great, but what’s the catch ? Well, Rhino is a commercial software, and it was designed for Windows. An OSX version is in the making, but there isn’t a solution of getting all the great plugins like Grasshopper on the OSX version yet, so it’s best to stick with Rhino for Windows for now. I used it in VirtualBox using XP.

Grashopper is a pretty impressive tool. It’s a free plugin that allows the user to create generative/algorithmic designs with no prior programming language knowledge. Although there is a scripting language available called RhinoScript, it’s based on VB Script and personally, I hate the syntax. It seems like Rhino 5.0 will have support Python scripting which I look forward to try, but back to Grasshopper. I say no programming language, I mean, you use a visual programming language paradigm based on nodes. Blender uses nodes for shaders, 3dsmax’s ParticleFlow system is based on nodes and C4D has the Xpresso editor. All similar in look but different in what they do. Grasshopper on the other hand reminded me more of MaxMSP/PureData. You can link geometry you draw in Rhino to Grashopper(GH) nodes or create points from scratch. You start logically from points, then you link them to make lines, then you link them to make surfaces, and so on. GH provides plenty of nifty tools and is quite flexible.

Kangaroo is a Grasshopper add-on for physical simulations. Once you’ve got a design in Grasshopper you can apply physical properties to it and run simulations straight from the Rhino interface, which is quite convenient.

Lobster IK is a GH setup by Daniel Piker who developed Kangaroo and although at it’s start, Lobster helps with RoboFold simulations.

And yes, it seems everything linked to Rhino will bare animal names :)

1 The workshop kicked off with making paper prototypes. The goal was to play with different techniques(like repetitions, intersections,etc.) to get a feel for what can what can’t be done and what kind of folds restrict movement and how. It was a very interesting process. The computer might make some aspects easier, but nothing beats the world world (so far). I am easily fooled that the computer is much more than a tool, using it on a daily basis, but I was pleasantly surprised by the process of using indispensable simple design tools. I didn’t need any manual to use them(pen,paper,ruler and scalpel.), I could dive right an quickly prototype.

7 The next step was to scan a design and get it into Rhino, from there we exported models to .dxf so we can also try them in Rigid Origami. The process sounded easy, just marking mountain and valley folds in red and blue lines for Rigid Origami, but in practice I found that simpler designs worked better than complex ones which did not work at all. You can see a screen grab from Rhino showing the same fold pattern in 3 version, one simpler than the other. Also, I’ve added a couple of images from Rigid Origami. The next step was to create a parametric version in Grashpopper, which is why the surface was ruled mostly using even steps. After that we played with Kangaroo to get a feel for doing physical simulations on the model.

3 Keywords like ‘ruled surface, curved surface’ flew through the room, and it reminded me of the Graphic Design I started in Bucharest in 2005 (and never finished). We had a pretty interesting course taught by an engineer on how to fold paper. I barely remember some notions about different types of course, and what kind of resistance properties it gave to the paper. The workshop did remind me of the joy of simply making things and made me realize I spent way too much time on a computer. The physical world has it’s limitations, but the kind of intuitive thinking that comes from working with real object is something I miss. I am not sure one way(computer) or another(physical) is better, as both have advantages, but I do believe achieving a balance between the two is the answer. Using the advantages of one technique to fill in the short comings of another.

The second day we got paired to design surfaces that would fit a pretty nifty window pattern. I got paired with Dr Kontovourkis Odysseas who teaches Architecture at the University of Nicosia in Cyprus. I must admit I was a bit overwhelmed at the workshop, not only by the amount of new information (which made me wish I picked up Rhino/Grasshopper earlier), but also by the rest of the attendees. I was the youngest, and came from a pretty different background, where the closest thing would be making 3D models in an abstract world. Most of the attendees were architects from different parts of Europe. Most of them were German speakers, although they weren’t from Germany. My colleague was kind enough to get me up to speed with Grasshopper and we started using designs from the previous day to fit on the window pattern.

2 Again simplicity won. Initially we had a folding with quite a few folds in, but it turned out not only it was hard to parameterize, but it also wasn’t very scalable. We started from scratch and got a parametric design. It was a challenging experience, but a fulfilling one. The talented people at Metropoltan Works were a pleasure to learn from and I was impressed with their facilities for 3D scanning and printing.I seem to find cutting and creasing paper very relaxing and I enjoy the different type of thought process. Looks like I found a way to do 3D, but spend a bit more time away from the computer.

Aknowledgement: the image at the top belongs to Irena Vucinic and was ‘kindly borrowed’ from the CurvedFolding website.

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