This instructable demonstrates and explains blooms, a unique type of sculpture I invented that animates when spun while lit by a strobe light (or captured by a video camera with a very fast shutter speed).
Unlike a traditional 3D zoetrope, which is essentially a flip book of multiple objects, a bloom is a single coherent sculpture whose ability to be animated is intrinsic to its geometry.
What you are viewing in each of the above videos is a bloom spinning at 550 RPMs while being videotaped at 24 frames-per-second with a very fast shutter speed (1/4000 sec). The rotation speed is carefully synchronized to the camera's frame rate so that one frame of video is captured every time the bloom turns ~137.5º—the golden angle. Each petal on the bloom is placed at a unique distance from the top-center of the form. If you follow what appears to be a single petal as it works its way out and down the bloom, what you are actually seeing is all the petals on the bloom in the order of their respective distances from the top-center. Read on to learn more about how these blooms were made, why the golden angle is such an important angle, and how these are related to the Fibonacci numbers. You will also find some tips for constructing the turntable and strobe light required to animate blooms.
Blooms are available at Shapeways, a 3D printing service.
The placement of the appendages on blooms is critical to the success of the animation effect. The positions are based on a specific phyllotaxy (i.e. leaf order) used by nature in a number of botanical forms, including pinecones, pineapples, sunflowers, artichokes, palm trees, and many succulents.
The photo above shows just such a succulent. I have numbered the leaves from youngest to oldest. If you follow the numbers in sequence you will find that each leaf is approximately 137.5º around the core from the previous leaf. 137.5º is a very special angle, called the golden angle, based on the golden ratio. The golden ratio is such an important number in mathematics that it's been assigned to the greek letter α (phi). When the golden angle is used by nature as a growth strategy it leads to the formation of spiral patterns. If you were to count the number of spirals in these patterns you will find that they are always Fibonacci numbers (e.g. check out the spirals on these pinecones).
In designing the blooms, I used essentially the same method employed by nature. I placed the appendages one-at-a-time starting from the top-center, positioning each appendage 137.5º around the center from the previous appendage and also a little further out and/or down.
So when I animate these blooms by spinning them with a strobe light (or video camera) I am, in a sense, recreating the process that I used to make them in the first place. Below are two stop-motion animations of some of my earlier work with Fibonacci spirals. You may these helpful in gaining a better intuition about how this animation technique operates.
The first animation shows a self-similar tiling, in which every piece is a unique size, but all pieces are the same shape. In the video each piece is removed (and later added) at an angle of ~137.5 degrees from the previous. Note: this is not CGI (computer-generated imagery); it is a stop-motion animation of actual laser-cut pieces of MDF.
(BTW, if you would like to make one of these Fibonacci tilings for yourself, check out my instructable, which includes the cutting file.)
The second animation shows the TransTower, a sculpture based on the same geometry as the tiling above. The transformations in this tower result entirely from rotating the individual layers by the golden angle with respect to their neighboring layers. (Note: this is not CGI; it is a stop-motion animation of actual laser-cut MDF.)