Weta has updated their website with around 8 different breakdowns of their contributions to the visual effects of Avatar. Showing the multiple passes and plates used in the shots, they showcase not only their CG work but the motion tracking work used for the mech robots.
Randall Hand
Randall Hand is a computer graphics programmer and news junky that's been working in the field for the last 15 years. He's responsible for visualizations generated on some of the most powerful supercomputers in the world, ytnef, mullion support in ParaView, and VizWorld.com.