The Walk Cycle for Quadrupeds

A quadruped walk is essentially two biped walks linked together, but out of phase with each other. When a biped walks, the shifting weight on the pelvis causes the up-down motion just described. For a quadruped, the same weight shifts occur for the pelvis and the shoulders.

Quadrupeds have different proportions than human bipeds. In particular:

• The rib cage is elongated downwards, unlike the flatter human rib cage.
• The shoulder blades lie along the side of the rib cage, not on the back.
• There are no collarbones.

  The lack of collarbones gives the shoulder blades more freedom. This affects weight distribution on the front legs.

  When you use Biped to animate a quadruped, its “clavicle” parts behave more like shoulder blades.

In spite of these differences, and some others we will mention later, a 3ds Max Biped can model a quadruped quite well. This tutorial uses a 24-frame cycle, which comes to one step per second for each pair of feet.

Preparation for This Tutorial

• If you have not already downloaded the tutorial files (MAX scenes and other assets), download them now and unzip them into a project folder called \Autodesk 3ds Max 2011 tutorials. See Where to Find Tutorial Files.
• On the Quick Access toolbar, click (Project Folder) and set your current project to Autodesk 3ds Max 2011 Tutorials.