Try the Tapeworm

Some people have shown interest in my Tapeworm script, so I'm posting it here for anyone to try.

Download Tapeworm v002

There are some notations inside the VB script explaining what is going on.

Basically, the script deals with the surface as if it were a long series of connected planar quads and then outputs the vertices of those flat surfaces as two lists of points. These points can be made into either polylines or interpolated curves, resulting in either a faceted or a smooth surface..

The two most important inputs for the script are "bend" and "twist". They should be lists of values that determine the curvature for each segment and the direction of this curvature. Please note that both lists should be equal in length. Also, the more values (steps), the more accurate the surface will be. The resulting surface should become single-curved (developable) and unroll to a straight strip.

Some photos and videos.

Good luck! Feedback is welcome.

Raw grasshoppers should be eaten with caution, as they may contain tapeworms. http://en.wikipedia.org/wiki/Grasshopper

Tapeworm script with sliders

MD-slider controlling Bending on Y-axes and twisting (left/right) on X-axes. Surface is Baked to Rhino and then unrolled to become flat and straight. Other versions here:

Tapeworm script

"Tapeworm" is the working title for a little script I'm developing. It will produce a long thin developable surface that unrolls to a straight strip. The curvature (bending + twisting) is controlled by two lists of values.

Developable curved strips in Grasshopper

A script in Grasshopper that will produce rather complex surfaces that are perfectly developable and they will also unroll to straight strips. Thanks to Graph Mappers (one for bending and one for twisting) the shape is relatively easy and intuitive to adjust.

(The surface in the top left corner of the image is quite similar to this one.)

I'm very pleased with these results!

Scripted 3d Bending

Fueled by a question from Jesper Thøger Christensen, I've continued to work on scripted 3d bending, something I started a while ago. At the moment it will just produce a helix (constant bend + constant twist), but I'm hoping to get some more elasticity in there.

Elastica curves video

Download .ghx.

Guitar string + Grasshopper scripting

Trying to mimic the loop shape of a curved guitar string. The scripted curve has linear increasing/decreasing curvature (like a Clothoid or Cornu Spiral). Pretty good fit?! (Gray line is a shadow)

(Some people may recognize the photo from this post)

Bending curves inside two circles

This is a strange relationship that I discovered already in these tests. Aligned at the curve centre points, the endpoints of bending curves lay on two circles! Circle diameter = 4/5 of curve length.

UPDATE! 31 oct 2010: The link was wrong.Download corrrect .ghx file

Download .ghx-file (wrong)

Cornu Spiral curves scripted in Grasshopper

I also tried scripting the Cornu Spiral curves (described earlier) in Grasshopper VB:

When superimposed with the saw blade curves it shows a much better fit, even though the overlap is not 100%:

(I remember that the last drop shape was a bit hard to orient correctly when drawing it, because it had both supports in one point.)

Please also note that my scripting skills are very basic, so I may very well have made errors when producing the elastica curves and cornu spiral curves.

Elastica curves scripted in Grasshopper

I tried some Grasshopper scripting to produce elastica curves.

(The script is really basic, it uses Loop to copy and rotate a line a bunch of times. The Sin values between 0 and 1 Radians are used to vary the amount of rotation. To get many curves at the same time a range of values are fed into the VB script component.)

Below are the curves that I drew manually along the saw blade:

To my surprise it's quite a bad fit as can be seen in the image below, showing both sets of curves superimposed:

The typical "drop shape" (that appears when the ends of the curve meet) seems too wide and low. Also curves seem to go in the wrong direction (see at left arrow).

Email from Oliver David Krieg

I was contacted by Oliver David Krieg, from the University of Stuttgart, Faculty for Architecture and Urban Planning. Oliver is one of the students in this years design studio called "Material Systems I: Reciprocities" tutored by Moritz Fleischmann and Christopher Robeller at the Institute for Computational Design (ICD) led by prof. Achim Menges.

They are investigating the properties of wood very thoroughly and of course bending geometry is one of them.

Rhino and scripting are among their tools and the goal is to develop a material system with interconnected elements that can react (passively) to surrounding influences.

It will be very interesting to see how this will develop. Thanks for getting in touch Oliver!

(Photos by Oliver David Krieg)

Twister

I discovered it was possible to replace a number with a list of numbers as an input to a VB.Net-script i Grasshopper and produced this rather weird model:

(Rendered in Maxwell)

Bending Structure

I used mirrored segments of the cornu spiral to create these arches.
You can download the grasshopper file here:
http://omkrets.se/grasshopper/MN-002-bending-structure.zip

This script generates the cornu spiral.

Cornu spiral in Grasshopper

A test with construting a cornu spiral in Grasshopper.
Script written in VB.NET. Download .ghx-file below:

http://omkrets.se/grasshopper/MN-001-cornu-spiral.zip

Generative components

 With GenerativeComponents (GC) I tried to mimic bending in 3d.

This shows an attempt to generate cornu spirals in GC. Not quite right - but beautiful!

Here I used scripting in GC to get a twisting strip.