Select the biped. > Motion panel > Keyframing rollout
Use controls on the Keyframing rollout to set and delete keyframes, copy and paste biped posture, mirror a biped animation, and select or change keys using Set Multiple Keys. You can also bend the horizontal center of mass track around a selected horizontal key.
To create a "high step" type walk from a default biped walk cycle using Set Multiple Keys
Create a walk cycle for the biped in Footstep mode.
Click Set Multiple Keys to display the Set Multiple Keys dialog.
Turn on Left Leg, Right Leg, and Move, then click Select.
All the Move keys are selected for both legs. Move is the leg state between footsteps.
Rotate either of the biped upper legs up, then click Apply Increment.
The rotation is applied to all the selected biped leg keys.
Close the dialog and click Play; the biped now has a high step walk. Open Track View and look at the left and right biped leg tracks; all leg keys in the Move state are white (selected).
To bend the horizontal center of mass track
On the Track Selection rollout select the horizontal track.
On the Display rollout turn on Trajectories.
Turn on Sub-Object Trajectories.
Select a key on the trajectory in the viewports.
Use the Horizontal Bend spinner to bend the horizontal path.
To edit keys on the Center of Mass trajectory
Load a Freeform animation.
On the Key Info rollout turn on Trajectories.
On the Track Selection rollout click Body Horizontal or Body Vertical.
Turn on Sub Object Trajectories at the top of the Motion panel.
In the viewports select and move keys on the Center of Mass trajectory.
To copy and paste an entire biped track
Make sure that Copy Track is active.
This is a three button fly-out, choose the Copy Track button.
Select the part(s) of biped corresponding to a track or set of tracks that you wish to copy.
Click on Copy Track.
The track(s) are copied to memory.
Click on another biped.
Click on Paste Track or Paste Opposite Track.
The entire animation track is pasted to the selected object(s).
To switch the left and right arm tracks
Select both arms (any part of the arm).
Click Copy Track.
Click Paste Opposite Track.
Set Key: Use either Set Key or turn on the 3DS MAX Animate button to create keys when you are moving biped objects. You must use Set Key for certain operations such as anchoring arms and legs or specifying an IK Blend. 0 is a keyboard shortcut for setting keys.
Note: If 3DS MAX bones using the IK Controller or 3DS MAX Particle Emitters are linked to the biped, or if you are displaying 3DS MAX trajectories or ghosting, the Animate button must be on while the biped is positioned. These objects update their parameters in real time as they are positioned.
Delete Key: Deletes keys at the current frame for the selected biped object(s).
By default biped arm, hand and finger keys are stored in the clavicle track. If you delete any one of these objects, you lose positions for the rest of the arm objects at that frame. If you plan on extensive hand animation, turn on Arms in the Separate Tracks group of the Animation Properties rollout, this creates separate tracks for each biped arm object. Deleting an upper arm key will preserve hand and finger keys.
Anchor Right Arm-Left Arm-Right Leg-Left Leg: Allows you to fix the location and orientation of hands and feet temporarily. Use anchors when you are setting up animation with inverse kinematics Object space, in which the arm or leg follows an object in the scene. Anchors ensure that the arm or leg keeps its alignment until you set the second key that establishes the Object-space sequence.
Note: Anchors are no longer necessary because of improvements to the IK system. When you use Set Planted Key in the IK Key Info rollout the limb is positioned to the previous IK key (join to previous IK Key).
Three button flyout
Copy Posture-Copy Pose-Copy Track: Use Copy Posture to copy selected biped limb(s) posture. Use Copy Pose to copy the entire biped posture. Use Copy Track to copy the entire animated track from a biped object. You can then paste this posture, pose or track onto the same or a different biped. Copy Track can be used to copy tracks from one biped to another, from one limb to another, and from the left to right or the right to the left side of the biped.
A handy technique is to create an extra biped for posture storage. Postures that you will use frequently are applied to this biped at different frames. Then, when you need a particular posture, use the time slider to move to the appropriate frame, select the biped limbs to copy, and click Copy Posture. Then select the biped you are animating and click Paste Posture.
Tip: Use Copy Posture and Paste Posture to copy the first frame to the last frame in a looping animation.
Paste Posture/Pose/Track: Pastes the position and orientation from the posture buffer onto the currently selected biped. Pastes an entire animation track onto the biped.
This is useful for copying a pose from one biped to another. You don't have to select the same objects on the biped you want to paste the pose onto. The posture buffer retains information on which objects were copied. Paste Posture will automatically paste the pose onto the appropriate biped objects, even though they may not be selected.
Note: Turn on the Animate button before pressing Paste Posture to set a key. If you don't have the Animate button turned on, you will need to select the appropriate object(s) and press Set Key to store the new posture.
Paste Posture/Pose/Track Opposite: Pastes the position and orientation from the posture buffer onto the biped objects on the opposite side of the selected biped. Pastes an entire animated track onto the opposite side of the biped.
This helps you create symmetrical poses and movements. Use Paste Posture Opposite in Figure mode to speed up the process of aligning the biped to the mesh. Perfect the fit of the right arm, hand, and fingers; copy them, then use Paste Posture Opposite to copy the changes to the opposite arm.
Mirror: Mirror the entire biped animation.
Set Multiple Keys: Select keys using filters or apply a rotational increment to selected keys. Use this to change periodic motion keys in Track View. Displays the Set Multiple Keys dialog.
Use Set Multiple Keys to edit a default walk or run motion created in Footstep mode. Open Track View, select all the leg keys in the "move" state using the State Filters in the Set Multiple Keys dialog and then apply an increment to all of these keys, for example.
Set Parents: When a limb key is created, keys are created for the parent objects also if Set Parents is turned on. Use Set Parents with Separate Tracks turned on on the Animation Properties rollout.
Set Parents is used to store the position of the entire limb when a biped limb is moved using inverse kinematics instead of rotated using forward kinematics. For example, if Set Parents is turned off and Separate Tracks are turned on in the Animation Properties rollout for the biped arms, then the arm will snap back to its original position if you transform the biped hand.
If Separate Tracks are turned on for a biped body part, then turn on Set Parents. This allows you to use the Move transform to position the biped limbs.
Note: Separate Tracks, on the Animation Properties rollout, adds biped object transform tracks.
Bend Horizontal: Bend the horizontal center of mass track around a selected horizontal key.
Select the center of mass horizontal track, turn on trajectories, turn on Sub-Object, then select a key on the trajectory and use Bend Horizontal to bend the path (trajectory) about the selected key. Bend Horizontal works in both footstep and freeform animation.
Note: You can also move vertical and horizontal Center of Mass keys on the trajectory.