I mentioned in an earlier post that I thought the head would require the most complicated rig to work. Today’s post is to show that 1) I was sorely mistaken, and 2) the leg rig is quite interesting and borrowed a setup often used for the hind legs of cat and dog rigs. More after the jump!

The legs are made up of multiple joints, so unlike a bipedal leg, there are multiple “knees” to take into consideration. Driving the entire leg with a single IK chain is the simplest approach, but limits the amount of play with the extra knee joints. On the other hand, making multiple IK chains to express the limb allows more flexibility, but makes leg placement unwieldy. The setup I’m using will offer the best of both worlds since it’ll use both setups at the same time. The base skeleton is made up of multiple IK chains, and these chains are driven by a singular IK chain using a duplicated skeleton. The setup is connected to three animation controls. There’s a main control, a pole vector control to pivot the knees without shifting the foot, and a pivot control to tilt the leg around the foot. The pole vector controls have the ability to switch parents between either the body, world, or leg control.

It took a few passes to get the setup just right and then I repeated the process across the other legs and did some cleanup of the scene (all the duplicated joints were cluttering up the outliner).

Segmented Ik handles that are parented to "Master" and animation controls. These are directly connected to the main skeleton.

Singular IK Chain that drives the entire leg named "Master"