9

Adjusting Vertical Motion 881
immediately preceding or following an airborne
period.
You can edit the Ballistic Tension parameter only at
Body Vert ical key frames where the body touches
dow n (a Touch key) or lifts off (a Lift key). On the
Motion panel Track S election rollout (page 2–945),
Body Ve rtical must be selected and a key must
bepresentatthecurrentframe.Withfootsteps,
a Bo dy Vertical key is a lways set automatically at
the landing footstep’s Touch fr ame and the takeoff
footstep’s Lif t frame.
Ballistic Tension can range from 0 to 1, with 0.5
as the default va lue. Increasing Ballistic Tension
to 1.0 makes the legs s tiffer at takeoff or landing.
Decreasing the tension to 0.0 makes the legs
springier and less stiff.
Ballistic tension determines springiness of landing.
(Left = 0.0, Right = 1.0)
Dynamics Blend
The D ynamics Blend parameter in the Dynamics
& Adaptation rollout (page 2–980) determines
whether biped dy namics or spline dy namics will
be used during airborne periods.
With biped dynamics (page 3–916),theheightand
trajectory of the biped during airborne periods
is determined by gravity calculations and other
biped-specific information.
With spline dynamics (page 3–1015),the
airborne height and trajectory are not set for you
automatically; you must set them manually with
keyframes.
When Dynamics Blend is set to 1, biped dynamics
are used. At 0, spline dynamics are use d. You
can animate this value to switch between the two
during your animation.
Procedures
To locate ver tical center of mass k eys:
1.
Select any part of the biped and access
the Motion panel.
2. On the Track Selection rollout, click Body
Ve r t i c a l .
3. Use the Next Key and Previous Key
buttons on the K ey Info rollout to jump to the
next or previous center of mass Body Vertical
keyframes.
Tip: If the selected vertical COM key is a
touchdown key from an airborne period, you
can change the Ballistic Tension par ameter on
the Key Info rollout to control knee bend. Turn
on Trajectories on the Displa y rollout to view
how changing parameters affects the trajectory.
To set a Body Vertical key:
1.
On t he Track Selection rollout, click Body
Ve r t i c a l .
2. Turn on Auto Key.
3. Click Select and Move on the main
toolbar .