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Animating Pivots 763
Wa rn in g:
DO NOT
usethelargeSetKeysbutton
found below the viewports when animating a biped.
Doing so will cause unpredictable results. Instead,
always use the Set Key buttons found the Key Info
rollout.
If you are animating a walk cycle or
an intricate hand animation, then you should make
use of the three different types of set k ey buttons
in the Key Info rollout. Each set key button applies
different IK constrai nts, depending on whe t her a
foot or finger is in a planted state, a move state, or
a sliding state. For more information on the three
set key buttons, see
Key Info Rollout (p age 2–809)
.
You can also set keys to m a ke hands and feet follow
astationaryoranimatedobject.See
Animating IK
Attachments (page 2–766)
.
If a Bones system using the IK cont roller or a
part icle emitter is linked to the biped, the Auto Key
button must be on in order to position the biped’s
limbs. This is also true for biped objects i f you turn
on 3ds Max Trajectories at the top of the Motion
panel, or if you choose Views > Show Ghosting.
TheSetKeyoptionsontheKeyInforollout
have the advan
tage that you can easily experi ment
with different pos es for your chara cter without
unintentionally setting keys as a side-effect. Use
the Set Key bu
ttonstocommitthechangesyou
make to the pose. The Auto Key mode approach
is especially useful when you make adjustments
to keyframe
sthathavealreadybeenset,orifyou
are used to working with Auto Key in3ds Max and
tend to forget to click the Set Key buttons.
Tip: UseSetKeytoinsertakeyonaframewhere
a key doesn
’t exist. You’ll often want to refine the
motion using controls in the K ey Info rollout,
w ithout selecting and moving an object in the
viewpor
t.
K eyboard shortcut: Pressing 0 (zero) is equivalent
to clicking Set Key on the Key Info rollout.
Make sure that the Keyboard Shortcut
Override Toggle is active to use character
studio–specific shortcuts.
Gr ound Pl ane Colli sion D etection for the
Pelv i s a nd Feet
When one or two feet are planted, and the pelvis
or a planted foot is rotated, char acter studio
detects collisions of the foot and its toes with the
ground plane defined by the planted foot’s footstep
or pivot point. As the pelvis or foot is rotated,
character studio uses inverse k inematics to a lter
the rotations of the leg joints so that the foot and
itstoesdonotgobelowtheplanedefinedbythe
footstep or pivot point.
Note: A biped foot on a sliding footstep is a special
case.Thebipedfootcanbemovedtoanyposition
and orientation for the duration of the footstep.
Note: Changing rotation v alues for the legs and toes
also maintains collision detection, but the position
adjustment is not made until you set a key.
Animating Pivots
In both freeform and footstep animation, pivots
allow you to rotate the biped’s hands and feet
around various points. For example, by activating
a pivot on the ball of a foot, you can rotate the f oot
around the ball of the foot. The biped’s hands and
feet have the same number of pivots, and pivot
location is similar. Pivots are active only if the
biped hand or foot is in world or object coordinate
space. In a walking motion, you can pivot on the
heel first, then on the ball of the foot, and finally