The controls on the Dynamics & Adaptation rollout let you specify how to create biped animation. Here you can modify gravity strength, set dynamic properties for keys generated by newly created footsteps, determine the number of transform tracks available on the biped, and prevent key adaptation.
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Select a biped. >
Motion panel > Dynamics & Adaptation rollout
Biped Dynamics and Spline Dynamics
These parameters specify how character studio creates new biped center-of-mass keys, which determines how you work with the biped. Turning on Spline Dynamics will create center-of-mass keys without gravity or balance calculation for newly created footsteps. This may feel more familiar to the new user who is 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 change from one method to the other on a per-key basis or for the entire animation at any time.
Interface
- 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 leave the ground.
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Biped Dynamics Creates new center-of-mass keys using Biped Dynamics.
Keys for the center-of-mass (COM) 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
Body group 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.
Footstep Adapt Locks group
When you change a footstep’s position or timing, Biped automatically adapts existing keyframes to match the new footsteps. The Adapt Locks settings let you preserve the positions and timing of existng keys for a selected track.
The adapt locks need not 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 Footstep Adapt Locks group Body Vertical Keys, access Footstep mode, select all the footsteps, and move them up along the world Z axis. The footsteps are repositioned and the legs adapted, but the upper body retains the same motion rather than being raised with the footsteps. Then turn off Body Vertical Keys, and the upper body still retains its original motion.
Use Footstep 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 retiming the touch, plant, and lift keys. The biped upper-body keys will retain their exact motion.
- Body Horizontal Keys
- Prevents adaptation of body horizontal keys when footsteps are edited in space.
- Body Vertical Keys
- Prevents adaptation of body vertical keys when footsteps are edited in space.
- Body Turning Keys
- Prevents adaptation of body turning keys when footsteps are edited in space.
- Right Leg Move Keys
- Prevents 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
- Prevents adaptation of left leg move keys (a leg move key, is a leg key between footsteps) when footsteps are edited in space.
- Freeform Keys
- Prevents 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
- Prevents 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.