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Choosing a Gait 861
• What is the sequence of the footsteps? This wil l
determine the footstep numbers.
Footstepsalwaysbeginwiththenumber0.
Number them in your diagram if you can.
• Is each footstep a left or right footstep?
Pl an ning for Footstep T imi ng
• What is the support relationship between lef t
and ri ght footsteps? In other words, does the
timing of the footsteps resemble a walk, run
or jump pattern? A character doing a foxtrot
or waltz, for example, is actually moving with
“walk” timing – the character shifts weight
from one foot to the other.
• How long, in frames, should each footstep b e ?
How long are the biped’s airborne periods?
• Arethereanyperiodsoftimewherethebiped
is standing on two feet for a while?
Ch o o sin g a Gait
A gait is a method or pattern of moving on foot.
When you create new footsteps,
thetimingisdeterminedbythegaityouhave
chosen (Walk, Run, or Ju mp) and the parameters
for that gait. You must choose the gait before
parameters can be set.
Choosethegaitthatmostcloselyapproximatesthe
type of movement you want to create. You can alter
or adjust the gait after footsteps have been created.
Walk Gait
In a walk, at least one foot is always in contact w ith
the ground. A period where one or both feet are in
contact with the ground is called a support period.
Ifbothfeetareontheground,thisisknownasa
double support period.
Turn on Walk before creating footsteps to
create this type of gait.
The gait parameters of a walk are:
Wa lk Foot ste p —The number of frames that each
footstep remains on the ground.
Double S uppor t—The number of f rames in a
double support period, tha t is, when both feet are
on the ground.
Run Gait
With running, both feet are never on the ground
atthesametime.Eitheronefootisontheground
during the support period, or the body is airborne.
While it is airborne, the body moves forward
horizontally at a constant speed. In general, the
longerthebodyisintheair,thehigheritmustfly
after lifting off from the supporting foot to stay
airborne for the specified period of time.
Turn on Run before creating footsteps to
create this type of gait.
The gait parameters of a run are:
Run Footstep—The number of frames that each
footstep remains on the ground.
Airborne—The number of f rames that the biped
is airborne, that is, when neither foot is on the
ground.
Jump Gait
Jumping is a special case of running. Both feet
are in contact w ith the ground at the same time,
or airborne at the same time. As with ru nning,
forward motion is horizontal and constant, but
vertical motion depends on the length of the jump.
Turn on J ump before creating footsteps to
create this type of gait.
The gait parameters of a jump are: