Ridge crease
A Ridge crease is a fold or a crease that extends inward from a polygon corner, at the same time acting as an angle bisector of that corner.
A Ridge crease is a fold or a crease that extends inward from a polygon corner, at the same time acting as an angle bisector of that corner.
Post is a part of a larger series (Creases): Hinge crease Ridge crease Axial creases A hinge crease serves two purposes. By definition, a Hinge crease is a line that defines polygons by the mere fact it surrounds it. Also, a hinge crease is a line around which a flap can rotate. Hence the name. It looks similar…
Analysing various Origami models one can see that oftentimes central vertical crease is missing. Why is it so, and why many authors resort to such a solution is something I will try to explain in this blog post.
Post is a part of a larger series (Design process): Origami design process (introduction) Origami design process – Part 2 Origami and circles Relationships between basic elements of an origami model Maekawa-Justin and Kawasaki-Justin theorems How to hide an unused paper in your Origami model? Can central flaps be free? Why is central fold opening so popular? Crease…
Origami is - I hope you understand - not some arbitrary, random paper folding technique that you use to create, almost by an act of magic, exciting paper models. Quite the contrary. Behind what is seemingly random paper folding there is a clear mathematical logic.
How many times you have heard that origami is based on circles? Is it true? and if so, what does it mean? Well, in this blog post, I will try to answer these questions.
All basic elements of an origami model (flaps and rivers) must be in the same relationship, both on the stick figure and the crease pattern. Reason is quite simple. Both stick figure and crease pattern are a graphical representation of the same future model. Therefore, it is not possible for a crease pattern to show one thing and for a stick figure to show something else.
Elias stretch is an origami manoeuvre that is often used while collapsing origami models based on the Box pleating technique. It was named after Neal Elias, who popularized it in the 1970s. The technique is very simple and is used to assemble flaps (polygons) located on the paper edge. Basically, wherever you have a polygon that forms a flap and it is located on the paper edge, you can use Elias stretch manoeuvre to collapse that polygon.
In this blog post, I would like to address the problem of unused parts of a paper. This problem is not uncommon in origami. As a matter a fact, you will stumble upon it quite a lot, and in this regard box pleating technique is no exception. Simply, when polygons and rivers are arranged on a square piece of paper, it is very likely that part of a paper will be left unused.