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400 Chapter 12: Animation
Inter face
Once you assign a Path constraint, you can access
its properties on the Path Parameters rollout in
the Motion panel. In this rollout you can add or
delete targets, assign weighting, and animate each
target’s weight value.
Note: When you assig n a Path constraint v ia the
Animationmenu,thesoftwareassignsaPosition
List controller to your object. In the Position List
rolloutlistyouwillfindPathConstraint. This
is the ac tua l path constraint cont roller. To view
the Path Parameters rollout with the constraint
settings, double-click Path Constraint in the list.
Add Pa th—Adds a new spline p ath that influences
the constrained object.
Delete path—Removes a path from the target list.
Once removing the path target, it will no longer
influence the constrained object
Weigh t—Assigns and animates weight values for
each target.
%AlongPath—Sets the percent that the object is
positioned along the path. This duplicates the
Value spinner in the track Properties dialog for the
Percent track in Tr ack View. If you want to set keys
to place an object at a certain percent along the
path,turnonAutoKey,movetotheframewhere
you want the key set, and adjust the % Along Path
spinner to move the object.
Note: The % Along Path value is based on the
parameterization of the spline path’s U value. A
NURBS curve mig ht not have an evenly spaced
Uvalue,soavalueof50%AlongPathmightnot
translate visually to 50 per cent of the NURBS
curve’ s length.
Follow—Aligns the object to the trajectory as it
follows the contour.
Bank—Allowstheobjecttobank(roll)asit
negotiates the curves of the spline.
Bank Amount—Adjusts the amount of the banking
to one side or the other, depending on whether the
val ue is positive or negative.
Smoothness—Controls how rapidly the roll angle
changesastheobjectmovesthroughbendsinthe
trajectory. Smaller values will make the object
more responsive to subtle changes in the curve,
while larger values smooth out jerking. The default
value is a good value for general damping along
the curve. Values below 2 tend to make the action
jerky, but va lues around 3 can be very useful for
simulating a certain degree of realistic instability.