Inventing Models

[Falcifer]

Eileen/Wolf's site was very good for info on box-pleating.

Currently it says: "Looking for Eileen's Origami Page? It'll be up here in a bit!"

For now, you could try the web archive page(s).

[Harpseal]

I sort of get box-pleating, but i have no idea what circle packing even is! Can someone sort of show/tell me (with pictures if possible?) because then i'll understand it better, or could someone at least show me some easy models that use circle packing, so i can see how it works, thanks!

[Falcifer]

The traditional crane uses circle packing. I don't suppose it was designed that way, but it happens to use it anyway. You can start with four flaps of equal length, which leads to the waterbomb base (or the preliminary base, depending on the way you fold it). With some petal folds, you get to the bird base.
You can also start with four equal circles and fill in the gap with another circle, which leads directly to the bird base

Robert J. Lang's Origami Design Secrets is probably the best resource for learning about design, especially circle packing. Not to mention that it's full of great models.
Also, you can play around with his TreeMaker program to see it in action (without having to do any of the maths). I've never had much luck with making a decent crease pattern with the program, though. Not that I've spent the time trying; it's probably far easier once you know how.

The basic idea is that a flap of paper uses up a certain amount of paper, which turns out to be a some portion of a circle. So, for however many flaps you want, you need that many circles (or part circles) to fit on the crease pattern/within your square. (It's just the center of the circles which need to be within the square). The size of each circle relates to the size of flap. Circles which touch lead to connected flaps.
A "river" is a gap between circles (or groups of circles) which represents a connecting part of the base. The narrowest part of the river will determine the width of the separation of flaps.

Lang's book describes it far better than anyone will be able to in a forum post. It did take me a while before it all clicked, though.

Lang also did a presentation for TED (here) where he explains a little about circle packing.

[Baltorigamist]

I first learned how to design using box-pleating, and honestly, using the circle packing/treemaker approach seems far more difficult to me. box-pleating will get you what you want a lot easier, if being slightly less efficient. I am trying to get better at circle/river packing, but I find it far trickier, so try both methods, and see what you like the best.

I agree with this 100%. I use box-pleating for most of my designs, but several of my non-BP designs were made using circle-packing. I usually just try to visualize the packing on the paper, figuring out where certain flaps would go, and assign approximate references to the flaps.
It's pretty much what I did with the Sonic design I was talking about earlier. Just stick a certain base in one corner, arms in two other corners, and screw with the rest until it works.

[cowburger13]

Eileen/Wolf's site was very good for info on box-pleating.

Currently it says: "Looking for Eileen's Origami Page? It'll be up here in a bit!"

For now, you could try the web archive page(s).

Oh, thanks

[Harpseal]

Thanks Falcifer! I get you, but i don't get how to apply it... Don't go through another massive post, i'll get the design secrets (edition two!!) and work it out. Thanks for your help!

[Falcifer]

Thanks Falcifer! I get you, but i don't get how to apply it... Don't go through another massive post, i'll get the design secrets (edition two!!) and work it out. Thanks for your help!

ODS does do a good job of explaining. Lang works through a few examples and there are plenty of pictures.

It's obviously a very powerful tool, but you don't have to just use one or the other. You can combine them if you like. Or use some other method of designing.

As long as you have a good idea of where your flaps are coming from and how to form them, it shouldn't matter which technique you use.

[Harpseal]

Box-pleating's working quite well for me at the moment, especially combined with the 22.5 degrees method, i don't know if i'd want another thing in there, but i may find i love circle packing, and it does fit in my designs very well and makes them much better.

[cowburger13]

circle packing is indeed a very good design technique. I taught myself by just examining crease patterns. You should also try it.

[Harpseal]

Iron man is circle-packed. That's one of the many things that confused me when i first decided to make it.

[Baltorigamist]

Many of the designs you'll come across were designed using some form of circle-packing--even box- and hex-pleats use a variation. (The only exceptions would be nonaxial bases.)

[cowburger13]

Generally, circle packed cp's are just a bunch of triangle molecules, and rabbit ears XD

[dragon]

I tried to use the 22.5 degree method, but I messed up at it. I started with circle packing, based on a 4x4 grid, but when I started to put creases in, the flaps weren't the lengths that they were meant to be, so when I tried to force them to be the right lengths, it all went horribly wrong. I don't get what I did wrong. Was it the circle packing?

[cowburger13]

Can you post picture of the cp you were trying to make? I may be able to help you

[Harpseal]

It doesn't sound like you're following a cp at all....