9

Understanding Footstep and Body Keys 867
Tip:
Alternatively, you can use layers (page 2–974)
to store an y upper body animations you want to
preser ve while you proceed with changes in your
biped’s footsteps.
Rules for Inactive Footsteps
When you click deact ivate footsteps, only selected
footsteps are deactivated. If you haven’t made
any changes to the default animation, it is
recommended that you deactivate all footsteps.
However , if you ’ve changed or added animation
keys to part of the animation, you might want to
deactivate only a portion of the footsteps.
When some but not all footsteps are currently
deactivated, limitations are imposed on the
changes you can make to footsteps:
• You cannot set, delete, mov e, or edit keys in any
way; footstep tracks are disabled in the Dope
Sheet.
• You can create footsteps only when the new
footsteps are among and adjacent to existing
inactive footsteps.
• Youcandeleteonlyinactivefootsteps,andat
least one inactive footstep must remain.
• You cannot deactivate a set of nonsequential
footsteps.
See also
Activating Footsteps (page 2–865)
Unders tanding Footstep and B ody
Keys
When you act ivate footsteps, keys are created for
biped body parts. Before you work with footstep
placement and timing, it’s essential that you
understand the default keys generated and how
they relate to footstep editing.
Leg S ta tes
A leg moving through a footstep has four states,
beginning with the foot on t he ground. T hen the
foot lifts, moves through the air, and returns to
the ground again. These leg states are labeled by
character studio to help you work with footsteps
and leg/foot keys more easily when editing
footsteps.
These states are referred to in these topics to aid in
understanding more advanced footstep concepts,
so it’s important that you become familiar with
them.
• Touch occurs at the leg keyframe where the
foot first touches the footstep, and always
corresponds with the start frame of a footstep
in Track V iew. The Touch state is always one
frame long.
• Plant occurs after touching, and before lifting.
It is always in between the s tart and end frames
ofafootstepinTrackView. ThePlantstateis
usually more than one frame long.
• Lift occursatthekeyframewherethefootlifts
off the ground, and always corresponds with
the end frame of a footstep in Track View. The
Liftstateisalwaysoneframelong.
• Move occurs while the foot is in the air, and
is always in the intervals b e tween footsteps in
Track View. In walking, while one foot moves,
the bo dy is supported by the other leg. In
running or jumping, there are periods where
thebodyisnotsupportedandmovesinmidair.
For more information on these keys, see Editing
Footstep Timing (page 2–869) .
You can display the current state of each leg
by turning on Leg States in Biped rollout > Display
group. The state name appears in viewports near
the foot, corresponding to the state at the current
frame.