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JellyFish is a new tool that works with Grasshopper and Rhino to enable various ways of modeling with attractive and repulsive forces. It is a generalisation of my popular Magnetic Displacement definition to 3-dimensions, along with some other improvements.

Any number of Sources and Sinks of variable strengths can be placed freely in space, and their combined effect can be used to move/orient/create any Rhino geometry based on points (including curves, NURBS surfaces and meshes).

The force model used is basically Coulomb’s Law for electrostatics, and a simple vector field integrator is included, so rather than just moving points along the tangent to the field at their start point you can actually move them iteratively through the curving field. This can help avoid particles crossing over each other:

Deformation of a grid shown with and without iteration

It also provides an alternative way of creating some of the kinds of surface usually modeled with Metaballs.

Because they are based on implicit surfaces, Metaballs produce an unstructured mesh. JellyFish on the other hand can produce a surface which keeps its explicit u v parameterization. This is potentially useful for fabrication or adding further layers of structure in Grasshopper or Paneling Tools.

Disclaimer: I am in no way endorsing the uncritical use of blobs in design!

JellyFish came about partly as a by-product of some more serious work with physical forces for structural modeling, but I thought others might find it fun to play with ( and maybe even useful )

You can download JellyFish here :

JellyFish.ghx (Shared under a CC Attribution Non-Commercial Share Alike license.)

I am currently available for long or short term work and writing custom scripts or GH definitions, as well as individual or group GH training. In the London area now, but would consider travelling or relocating for the right opportunity. Please do not hesitate to get in touch if you have any questions.

Also, I am thinking of running a Grasshopper Workshop in London soon. If you think you would be interested in attending, drop me an email with your details to pre-register.

click for some more variations

Fractal trees do seem very 80s, but I recently saw this nice interactive experiment (which was inspired by this), and couldn’t resist trying it out in a quick Grasshopper sketch.

It was easily generalised to 3D by using reference frames.
Just varying the positions of the endpoints of the first pair of branches produces a great range of forms.
When branches are of equal length to the trunk, with a separation angle of 2PI/3 and a twist of ArcCos(1/3) (the dihedral angle of a tetrahedron), the resulting tree is the skeleton of the Gyroid – the Wells(10,3)-a Net.

I think this would be a really fun thing  to link to some AR style 3d-tracking, so you could move a couple of fiducial markers around in space and have the model update in realtime.

The Medial axis or Voronoi Skeleton of a polygon is the set of all the points with 2 or more closest points on the polygon’s boundary. Another way of putting this is that it is the locus of the centre of all the maximal inscribed circles.

It is an important tool in computational geometry, with a wide variety of applications, from image recognition to finite element analysis. The closely related straight skeleton has also been used for generating ridge-lines for the rooves of buildings.

Here is a simple Grasshopper definition for generating the medial axis of an arbitrary 2d closed curve.

As I have written about earlier, this also generalises nicely to 3D

This video collects some of my recent geometrical play in Rhino/Grasshopper. I’ll be posting further explanations and definition files here over the next few days. Among the things shown are:

• A 3D random walk

• Some hinged tessellations

• A geodesic sphere from projected subdivisions of an icosahedron. ghx here

• An origami waterbomb base – the starting point for many origami designs (also, I found a neat way to interlock 6 of these to make an octahedron as shown in this video)  ghx here

• The continuous deformation between the helicoid and catenoid (see minimal surface associate families).

• Various combinations and hierarchies of Voronoi diagrams, proximity networks, vortex flows, Delaunay triangulations, and incircles (some inspired by Mario Klingemann’s experiments with Malfatti circles)

• 3D rotations and Orientation Entanglement

• Vogel’s Floret/Fermat’s spiral – A classic example of phyllotaxis. (evsc has some nice work on this)        ghx here

• 2D equipotentials

• and finally, the beginnings of some work with Vortex Filaments and the Biot-Savart law.

Good sources for inspiration on some of these themes are the books of Philip Ball and the huge collection of links at the Geometry Junkyard.

For a little more explanation of the mathematics of these functions of complex numbers, why I love them, and the architectural surfaces they can be used to generate, see my earlier post on rheotomic surfaces
Those coming from BoingBoing in search of Gnarl might also enjoy my 4D rotation animations or experiments with Cellular Automata.

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Continuing to explore corrugations which are rigidly foldable – ie. there is no deformation of the faces during the folding process.
This has links to some surprisingly deep mathematics – in particular the subjects of discrete differential geometry and integrable structure – Which have important architectural applications (such as finding planar panelings of curved surfaces) and also tie in with my earlier interest in minimal surfaces and circle packings.

The same principles can be naturally extended to other piecewise-planar surfaces such as the one above, which is rigidly foldable but does not unfold to flat.

Inspired and informed by the work of Tom Hull and Tim Hoffmann

My electric field sketch in Grasshopper controlling the metamorphosis of the MARS double corrugation pattern. Folded in Rigid Origami Simulator