The topics in this section deal with using freeform animation and inverse kinematics (IK).
Biped's inverse kinematics solution has three parameters set at each key of the arm and leg keyframe tracks.
Walking motions in both freeform and footstep animations should follow the rules of certain IK constraints. In both freeform and footstep animation, a footstep interval is the start and end of a sequence of IK constraints in world space, with IK Blend set to be greater than 0.0. A biped foot in the Move state should have body space turned on with an IK Blend of 0.0. By using these IK constraints, you can convert between the two animation methods seamlessly.
You can animate biped's body parts as you do other 3ds Max objects: by setting keys for postures at keyframes.
In both freeform and footstep animation, pivots allow you to rotate the biped’s hands and feet around various points.
While character studio was initially designed as an specialized program for animating two-legged, or bipedal characters, it works quite well for creatures that walk on four or more legs.
A biped can interact with other objects in the 3ds Max scene. Links between objects are usually static, unless you're using the Link controller. In character studio, such attachments are "animatable" as well; during the course of an animation, the links between the hands, feet, and objects in the scene can change as your character interacts with them.
