was originally designed for bipedal characters, that is, characters that walk on two legs. It uses a structured system of dynamics and balance to create secondary motion in the upper body, including arm swinging and tail swaying that is automatically applied when footsteps are used. By using default footsteps, you are assured that the biped's foot doesn't slide or pass through the ground, and that the foot easily rolls from heel to the ball of the foot as is common in a typical walk.
provides a more traditional method of animating to those familiar with 3ds Max, or other character animation systems. Keys are set by using the character studio Set Key tools found in the , or by turning on Auto Key mode, moving the time slider and transforming the biped parts.
Freeform animation includes preset key types called planted, sliding, and free keys; these make it very quick to lock a biped's foot or hand in space and get results similar to those of footstep animation.
You can convert back and forth between footstep and freeform animation within some limitations. While it is easy to convert any footstep animation to freeform, there are limitations on the conversion from freeform animation to footsteps.
Because of these limitations, a common workflow is to use footstep animation to rough out the animation, then convert to freeform to finalize the motions. The totally freeform animation is not bound by the rules of the footstep method, so it's easy to do anything you want, such as add keys at the beginning or end of the clip.
There might be times when you want to convert a footstep animation to a freeform animation, or vice versa. This can occur when someone gives you an animation file that's animated in one mode, while you prefer to work in the other.