Audrey St. John

Java applet demosDemos that quickly prototype approaches to gain intuition and
provide tools for demonstration.

Pebble Games for Sparse Graphs
Pebble games are based on an elegant and simple algorithm introduced by Jacobs and Hendrickson in 1997
for 2D barandjoint rigidity. We generalized the 2D game to a family of pebble game algorithms,
which characterize a counting condition called sparsity in graphs.


2D Motion Simulation for BarandJoint Frameworks
By adapting the ragdoll physics technique, introduced by the game industry, we can simulate
motion of barandjoint frameworks in the plane. Note that, because this simulation is not based
on Laman's condition for generic rigidity, it is able to handle frameworks in socalled
"special position."

