Archive for the ‘math’ Category

figuring out things with ORIPA

I have been playing with an origami pattern design tool called ORIPA, made by Jun Mitani (his blog here).

Once I figured out how to get it properly running on my Mac, it was pretty easy to figure out. here’s a handy tip for that. it needs latest java release 1.5.0; the mac still uses 1.4.2 by default, so you have to call the 1.5.0 version specifically to execute the runtime. I did this by stashing the jar file (the packed program file) in my origami directory, and created this shell script:


#!/bin/sh
/System/Library/Frameworks/JavaVM.framework/Versions/1.5/Commands/java -jar ~/origami/oripa012.jar


which I saved as /usr/local/bin/oripa on my machine; although you could just as easily save it to your desktop as a clickable icon.

anyhow, that bit of stuff aside, I was having problems getting it to properly fold some of my hexagonal design right- but I had seen other files which were more complex and folded quite well. So I uploaded some simple examples to the upload board for ORIPA, and I saw today that Mitani-san had written some information on his blog about how to fix the problem.

here’s his commentary from yesterday; it’s probably quite a bit more helpful if you run it through babelfish first.

basically, I was starting with this pattern:

and it was getting stuck. that was because there were several lines in wrong places, and 2 lines that had essentially 0 length- they were throwing things off. He suggested opening it up in a text editor and changing the coordinates of those lines so they can be properly deleted, which then allows it to fold properly.

It did so for him, and once I tried the same thing it worked for me also.

I’m not sure I can properly express how absolutely cool this program is- it lets you plot out all your crease lines and then not only can you export it as DXF (for import into tools like FreeHand or Illustrator) but you can hit the button and see the final folded rendition of your piece!

I’m working on a larger (permanent) page for this site on how to use it, and some english links for the various bits needed to make it run, but by all means check it out if you are so inclined. the download page is here; you’ll need to grab the oripa012.jar file, and for Windows you’ll need the latest version of the Sun Java Runtime Environment. You can grab the english version here; you’ll want the link titled “Download JRE 5.0 Update 6″ and then pick either the “Windows Offline Installation, Multi-language” or “Windows Online Installation, Multi-language”, depending on what kind of internet connection you’re using.

once you have that installed, it’s just a matter of double-clicking on the “oripa012.jar” file on your desktop to run it. it’s all in japanese, of course, so it takes some fiddling to use, but there aren’t a ton of options and the tools have relatively self-explanatory buttons. I hope to get a more comprehensive writeup done later for this wonderful program.

UPDATE: Mitani-san has released a localized english version of ORIPA! Here’s the English Language Page; ORIPA version 0.16 is the latest at this time, and is in english. -Eric (2005/02/16)

Posted in diagrams, geometry, math, my work, origami, origami tessellations, software | Comments (7)

additional comments on my most recent design

This is all in regards to the work mentioned in this post.

Jane says:

I wouldn’t do the triangular twists if I were you, it looks great this way.

I was wondering the other day about how you create your tesselations.
Melissande* designs the patterns and then create the folds that will lead to that pattern. I, on the other hand, like to mix folds (like in a chemistry lab) to see what patterns will come out of it.

Mélisande says:

The hexagon + teardrops in the center is an innovative and clever arrangement. It makes my think of this hindu dancing god with many legs and arms (can’t just now remember the name).

I’m afraid I don’t understand what you mean with “gear” : for me, it is the thing controlled by the handle you take in the right hand when driving a car…Surely this word has other meanings.

I hope you don’t mind me quoting you here! thank you, friends, for your commentary!

OK, to answer your questions (or try to, anyway…)

Jane: when I am thinking of things, quite often I just visualize in my head how I would want something to look. in this case, and sometimes in others, I draw it out in a little notebook or on a piece of scrap paper. I drew this one while I was sitting around in a meeting; you can see other pieces of silly drawings on it.

(click to make it larger.)

Once I had the general idea of what I wanted to fold, then I just started folding to see what would happen. for many types of intersections, I know how the paper will fold and how it will look, so many parts of it I already know- it’s just the unknown parts that are interesting, because I get to discover how to make them fold together. I usually know it can be done, so I only need to try it and see how it works to solve the problem. this is the part I enjoy the most.

Melisande: the central part actually can be made into a very nice “puffy star” shape- I like things flat, so I did not fold it this way, but it took that shape naturally until I squashed it completely flat. I had to borrow a camera today so it did not take very good photos; I’m going to wait until I fold a larger one to worry about it, though.

when I say “gear” I mean somewhat what you are thinking of- a gear, a cog, a wheel with spikes, something that belongs in machinery.

here is another doodle, to show what I mean:

(click to make larger.)

Gears interconnect with each other, and spin around- so it helps me to visualize how any particular crease intersection will flow, because I can assign directionality to the “spin” of it. this is almost like circle packing with a directional spin, I guess. it doesn’t hold true for the double-pleat folds (like Jane’s recent work), as they lack a directional bias. but yet in some ways they do, or they can be given one, so it still applies, I suppose.

it is an idea inside my head that is not well formed into a solid thought, so I’m still trying to decide how it works or IF it works as a usable concept.

but it’s one of the ways I think of things, especially if I am designing something inside my head which is complicated and I do not have paper to draw it out- then I just start assigning spinning wheels to each intersection and I can figure out where I need to fold.

that was an awfully long post! wow.

Posted in design, flickr photos, geometry, math, origami, origami tessellations, paper | Comments (2)

IT Conversations: Robert Lang - Computational Origami

IT Conversations: Robert Lang - Computational Origami

A 16 minute presentation by Robert Lang at OSCON 2005 on Computational Origami.

Here’s some more links to go along with the podcast:

Daniel Steinberg’s notes from the presentation, with links.

aallan’s flickr photoset which includes many of the slides from the Computational Origami presentation.

UPDATE: you can also listen to this conversation on NPR with Robert Lang. Thanks to Rozen on flickr for the link!

Posted in flickr photos, geometry, math, origami | Comments (0)

The Fitful Flog: The Three Card Monte

The Fitful Flog: The Three Card Monte

Philip has a seriously cool “wallet” fold, which gives you a hexagonal folding wallet which holds several ID cards/credit cards/whatever.

The best part, of course, is that his final version looks like a set of playing cards! now that’s just crossing the line into utter geek cool factor. (or at least in my opinion.)

well, really the bestest (yes, I said bestest) part is that he took the barcodes from his frequent purchaser cards and printed them onto the thing, so he doesn’t even need to carry those things around with him.

He’s got CP’s posted; they look swell using Adobe Acrobat Reader on my PC, but they are non-visible using Preview on my Mac (10.4.3). ack!

great work! thanks for sharing! oh, and they are CC licensed, so you don’t have to worry about the origami harpies chasing you down and hounding you for giving away the CP to people. double great!

Posted in creative commons, geometry, math, origami, paper | Comments (2)

industrial origami

Industrial origami

Found via future feeder.

very interesting process; looks like they have devised some methods for folding things from a single piece of sheet metal, including things like jack stands, boxes, 1U server chassis, etc. I’d love to watch the folding process for some of these, especially if it is completely roboticized.

Posted in design, geometry, math | Comments (3)

The origami tessellation artwork of Ralf Konrad

I first saw Ralf’s Origami Page a while back, and I really liked his hexagonal tessellation work- but I’ve only really discovered the breadth of it lately. Here are a few links showing off his great artwork.

http://ditelo.itc.it/people/gretter/brannenburg05/modelli_s/IMG_3256.html

http://ditelo.itc.it/people/gretter/brannenburg05/modelli_s/IMG_3254.html

and, of course, this one- the most interesting I have seen yet.

http://ditelo.itc.it/people/gretter/tassellazioni/konrad.html

do those look familiar? and this is from 2003! looks like we all got scooped here by Ralf. Although I would suspect we’re all just refolding designs by Fujimoto, anyway…

Posted in geometry, math, origami tessellations, paper | Comments (0)

The Fitful Flog: The 16-Sided Compass Rose Jar, Continued

Sorry for the multiple hits here, but I just find this stuff fascinating.

Philip has a 16 sided jar folded- I’m loving the unique and interesting geometry. definitely gives me something to shoot for in my folding abilities!

here’s the photo:

Follow the link for delicious goodness.

The Fitful Flog: The 16-Sided Compass Rose Jar, Continued

Posted in design, geometry, math, origami, paper | Comments (0)

The Fitful Flog: Pentagonal Compass Rose Box and φ-Quiddity

Pentagonal Compass Rose BoxOriginally uploaded by oschene.

Philip (a newly found origami folder to me) posted this spectacular Phi based fold, which is something like a flower/rose/box thing. Phi rocks my world, but I’m utterly unable to fold complex things out of it- something I’m still working on (pentagonal geometry isn’t the easiest thing to work with at times).

He also has crease patterns here so you can fold it! I’d suggest popping over and taking a look. His origami blog is also fascinating as well, and is a new RSS feed for me to take in on a daily basis going forward!

The Fitful Flog: Pentagonal Compass Rose Box and φ-Quiddity

Posted in design, flickr photos, geometry, math, paper | Comments (0)

Google Print shows me an interesting book!