# Any ideas for this one?

This is a wall hanging I found in doctor’s office today. It is about 30" wide and seems to be made out of fiberglass and then painted with streaks of fairly thick acrylic paint.

The shape is the Fibonacci spiral which is found in seashells, tornadoes, galaxies in space, and sunflowers. I thought it would interesting to make a 3D print of this geometry, but I have no idea where to begin. It’s easy to generate a Fibonacci sequence, but how to turn this into a spiral curve? And then how to create the continuous 3D relief surfaces? Could a 2-rail sweep do it?

Connect the corners with the same index or centroids of the boxes. That’s my guess.

UPDATE:

1 Like

I wouldn’t start with Fibonacci. Start with an exponential sequence of numbers. I.e. generate a linear range and then run them through an exponential expression. This will probably allow you to generate both coordinates on the spiral (linearly increasing angle, exponentially increasing radius) as well as the spacing between ribs.

2 Likes

Have a look at Nautilus Spirals. It looks like David is right and they don’t actually follow the Fibonacci sequence/Golden Ratio but are instead logarithmic.

The good ol’ google machine.

The file is there for download also

You can take some idea from that

2 Likes

It is, after all, your icon

For sure I like Ammonite,

4 Likes

Wow - thanks to all. I’ll be busy for a while now.

1 Like

Hi Laurent,
As you seem to be the number 1 expert for these shapes, I was hoping for some help -
For an art project, I need to model a cochlear shape

The artist believes that a Fibonacci spiral will be close to this shape

There are nice solutions around to produce the 2D spiral curve, but I’m not sure what would be the function to produce the height or the best method to implement it in GH.

Any help will be highly appreciated!
Many thanks,
Y

You could try Soft Move in Rhino or some Grasshopper - the closer to the centre the higher control point go.