Below are two videos made from the exercises shown at the DS10/Inter9 Grasshopper class at the Architectural Association.
The first video shows the trail left by points constrained by springs, end points and gravity. The Arch moves up and to the side, leaving a beautiful trace which reminded me of the pictures of Edouard Muybridge. It was done with Grasshopper and the free Kangaroo plugin by Daniel Piker.
The second video is a very simple example of recursion using Hoopsnake byVolatile Prototype for Grasshopper: A line rotates on another line and this new line becomes the currrent one on which the rotation is done and so one and so forth. Depending on the angle of the rotation and its location on the curve, these amazing patterns get created.