Select the biped. > Motion panel > Animation Properties rollout
Use these controls to specify the way you want to create biped animation. The parameters let you modify gravity strength, dynamic properties for keys generated by newly created footsteps, the number of transform tracks available on the biped, and prevent key adaptation using parameters in the Animation Properties rollout.
These parameters specify how new biped center of mass keys are created and therefore how you want to work with the biped. Turning on Spline Dynamics will create center of mass keys, without gravity and balance calculation, for newly created footsteps. This may feel more familiar to new users who are already familiar with spline interpolation.
Biped Dynamics calculates biped airborne trajectory, knee bend on landing and positions the biped to maintain balance when the spine is rotated. When parameters change, the biped adapts. Turn on Biped Dynamics and use this adaptation to your advantage.
You can always change from one method to the other on a per-key basis or for the entire animation at any time.
By default, biped uses an optimized method for key storage. For example, keys for the fingers, hand, forearm, and upper arm are stored in the Clavicle transform track. If you are more comfortable knowing that a transform track is available for each arm object, then use the Separate Tracks group to make these transform tracks available; transform tracks are displayed in Track View.
Tip: Separate Tracks are designed to be used with forward kinematics rotations. Using the Move tool to change the position of a biped limb with Separate Tracks turned on will require that you turn on Set Parents. If Set Parents is not turned on, then the limb you move will only be stored relative to its parent objects, and the new parent positions will not be stored. This will result in those parent objects snapping back to their originally stored location. Turning on Set Parents will insure that the position of the entire biped limb is stored.
Note: Separate Tracks are intended to be used as a preference. Turning Separate Tracks off and on will result in a key being stored for every biped object in the limb for the frames where any biped keys previously existed.
To create separate tracks for biped arms
Turn on Arms in the Separate Tracks group.
If Track View is open, notice that fingers, hands, forearm, and upper-arm now have a transform track. A deleted upper arm key will not destroy palm and finger keys.
To turn on Spline Dynamics for newly created keys
On the Animation Properties rollout, turn on Spline Dynamics.
Turn on Footstep Mode, if you haven't already.
Create new footsteps and create keys for inactive footsteps.
Balance Factor and Gravity are turned off. A jump created in Footstep mode has a flat trajectory; spine rotation does not alter the biped body to maintain balance.
To use Adapt Locks to prevent keyframe adaptation
On the Animation Properties rollout, select a track to lock.
The tracks you selected as locked are unaffected by footstep editing.
GravAccel: Sets the strength of the gravitational acceleration used to calculate the biped's motion.
By default, this parameter is set to accurately simulate Newtonian gravity as found on the Earth's surface.
At a value of 0, the biped still runs but the feet hardly get off the ground.
Biped Dynamics: Creates new center-of-mass keys using Biped Dynamics.
Keys for the center of mass Balance Factor and Dynamics Blend parameters are set to a value of 1. Biped calculates airborne trajectories and biped balance.
Note: Use Dynamics Blend on the Key Info rollout to set a vertical COM key that is a blend between Dynamics and Spline Interpolation; a value of 1 is full Dynamics, a value of 0 is full Spline interpolation.
Spline Dynamics: Creates new center-of-mass keys using full spline interpolation. All new vertical COM keys are created with Dynamics Blend=0, and all new horizontal COM keys are created with Balance Factor=0.
Adapt Locks group
Lock specified tracks to prevent automatic adjustments being made to those tracks when footsteps are moved in space or edited in time. All the locks except for Time work for footstep editing in space. Time, locks upper body keys when footsteps are edited in time (Track View). Adapt Locks only applies to a Footstep animation, not a freeform animation.
When you move a footstep in space or adjust footstep timing, Biped automatically adapts existing keyframes to match the new footsteps. Adapt locks allows you to preserve the exact position of already created keys for a selected track.
Adapt Locks does not need to be on all the time. For example, if you want to raise all the footsteps along the world Z axis, without changing the upper body position, turn on Adapt Locks Body Vertical Keys, turn on Footstep mode, select all the footsteps and move them up along the world Z axis. The footsteps are repositioned, the legs are adapted, but the upper body retains the same motion rather than being raised with the footsteps. Now turn off Adapt Locks Body Vertical Keys, the upper body still retains its original motion.
Use Adapt Locks Time to retain upper body motion while editing footstep duration in Track View. When the duration of a footstep is changed, the biped leg will adapt by re-timing the touch, plant and lift keys. The biped upper body keys will retain their exact motion.
Body Horizontal Keys: Turn on to prevent adaptation of body horizontal keys when footsteps are edited in space.
Body Vertical Keys: Turn on to prevent adaptation of body vertical keys when footsteps are edited in space.
Body Turning Keys: Turn on to prevent adaptation of body turning keys when footsteps are edited in space.
Right Leg Move Keys: Turn on to prevent adaptation of right leg move keys (a leg move key, is a leg key between footsteps) when footsteps are edited in space.
Left Leg Move Keys: Turn on to prevent adaptation of left leg move keys (a leg move key, is a leg key between footsteps) when footsteps are edited in space.
Freeform Keys: Turn on to prevent adaptation of a freeform period in a footstep animation. The biped's position during a freeform period will not move if footsteps after the freeform period are moved further away.
Time: Turn on to prevent adaptation of upper body keys when footstep duration is changed in Track View.
Note: Leg and foot keys for frames in which the foot is in contact with the ground are always automatically adapted.
Separate Tracks group
By default character studio stores a finger, hand, forearm, and upper-arm key in the clavicle track. The toe, foot, and calf keys are stored in the thigh track. This optimized approach to key storage works well in most cases. If you need extra tracks, turn them on for a specific biped body part.
For example, turn on Arms if you plan on extensive finger-hand animation; if an arm key is deleted, it will not affect the finger-hand keys. Notice that in Track View a transform track is now available for the first link of the thumb (stores all finger keys), hand, forearm, and upper-arm.
Arms: Turn on to create separate transform tracks for the finger, hand, forearm and upper-arm.
There is one finger track per hand. All finger keys are stored in the "Finger0" transform track, the first link of the biped thumb.
Legs: Turn on to create separate toe, foot, and calf transform tracks.
Ponytail 1: Turn on to create separate ponytail 1 transform tracks.
Ponytail 2: Turn on to create separate ponytail 2 transform tracks.
Spine: Turn on to create separate spine transform tracks.
Neck: Turn on to create separate transform tracks for the neck links.
Tail: Turn on to create separate transform tracks for each tail link.