Daniel Pikers KANGAROO

(As reported earlier in this previous post) Daniel Piker is developing ways to accurately simulate physical behavior in his Grasshopper component "Kangaroo".

In the latest release there are tools for simulating bending geometry.

This is nothing but a revolution for this investigation!

Never before have I been able to recreate bending geometry so accurately in an "artificial way". At the moment Kangaroo works very accurately for 2d-bending with both fixed and hinged ends and also in 3d for rods.

3d-bending of developable surfaces is a little more tricky and requires a careful setup to make sure the surfaces stay developable.

Kangaroo works in an iterative way by letting some predefined forces (like springs, bending resistance, pressure and gravity) affect the geometry, step by step, until (usually) a stable solution is reached. The beautiful thing is that all this is done in real-time, so you can play around with different constraints and setting and see the result instantly.
Of course, this investigation is not only about mimicking bending geometry, but also about understanding it. Kangaroo brings my understanding to a new level!

For more reading on how Kangaroo deals with bending, Daniel Piker has recommended a paper written in 1998 by S.M.L. Adriaenssens and M.R. Barnes called Tensegrity spline beam and grid shell structures, published in Engineering Structures 23 (2001), pages 29–36.

Many thanks to Daniel Piker for making and sharing the Kangaroo!

Kangaroo Bending + Reactivision

A video response to these photos by Amir Gazit. Thanks to Daniel Piker for this setup: Also thanks to Andy Payne and Jason K Johnson for including the Reactivision stuff in the latest FireFly. It's a lot of fun!

Realtime curvature analysis of a Kangaroo bending curve

Some more testing with bending in Daniel Pikers Kangaroo.
Kangaroo is a component for Grasshopper (Rhino).

Kangaroo Physics "Drop shape"

This is the closest approximation I have found so far in my quest for finding the Geometry of Bending. It's a fairly simple setup in Kangaroo. Pretty amazing how well it works! Thanks Daniel...

Bending simulation in Kangaroo

A very simple test in Kangaroo (only 8 control points) turned out to be very realistic in the way it moves. View it at Vimeo.

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