References to related work we consider interesting

• Animation Lab at Georgia Tech

Currently the leader in physically-based character animation. Great videos.
• Boston Dynamics, Inc.

Products for dynamic simulation. A spin-off from the MIT Leg Lab.
• Knowledge Revolution, Inc.

Makers of the Working Model dynamic simulation environment. Honest physics.
• MIT mobile robot lab

Once home of the six-legged robot insects. Sadly, no recent legged machines.
• McGill University Ambulatory Robotics Lab.

At last, a running machine without an extension cord.
• Free University of Brussels

Simulated and robotic runners.
• Michael van de Panne

Luxo climbs stairs.
• Search the Web for "Animats"

Web-Crawler finds most of the better known work. Fast.

Theory references - papers we've found useful

• Chris Hecker's home page

Hecker's articles in Game Developer Magazine are an excellent introduction to the field. A good place to start if the references below look difficult.
• QHULL

The biggest, best convex hull algorithm. Actively maintained; they've fixed bugs for us.
• Cameron's Enhanced GJK

The best polyhedral distance algorithm we've tried.
• University of North Carolina collision detection work

Source for I-COLLIDE, V-COLLIDE, RAPID, etc. Pioneers of modern of collision detection.
• Brian Mirtich

His version of Featherstone's algorithm. A modern C++ implementation of articulated body dynamics.
Also see his collision detection system, VCLIP
• David Baraff's tutorials

An accessible source for the impulse/constraint approach.
Good overviews of the simulation problem. His approach is different from ours, but worth checking out.
• Ernst Hairer

The most thorough researcher on numerical integration of stiff systems. Read about his book. Order his book. He's implemented most of the stiff integration algorithms, and compared them directly. All his code is in FORTRAN. He thinks about integrator control like a control theorist, and that seems to be the right approach.
• The DynaMo dynamics library

An impulse/constraint type dynamics library. Free and open source. In C++.
• The SOLID collision library

Gino van den Bergen's collision detection library. Free and open  source. In C++.
• Intelligent Motion Control with an Artificial Cerebellum

Russell Smith's thesis on legged locomotion.

May 25, 1999
info@animats.com