9

Spring Controller 375
funct ions the same as Linear Rotation, but uses
non-adjustable curved interpolation, and has the
following characteristics:
• Displays no controllers, key properties, or
function curves
•MovekeysinTrackViewtochangetiming
• Directly rotate objects in the viewpor ts to
change rotation values
S pr ing Co ntr oll er
Maintoolbar>CurveEditor(Open)>Selectatrackinthe
Track View hierarchy. > Track View menu bar > Controller
menu > Assign > Spring
Graph Editors > Track V iew – Curve Editor > Select a
track in the Track View hie rarchy. > Track View toolbar >
Controller menu > Assign > Spring
Animation menu > Position controllers > Spr ing
The Spring controller adds secondary dy namics
effectstoanypointorobjectposition.Theend
result is secondary mass/spring dynamics similar
to Flex. This constraint adds realism to generally
static animations.
When you apply Spring to an animated object,
itsoriginalmotionispreservedandsecondary,
velocity-based dynamics are applied. You can
cont rol the object’s mass and drag. When you first
apply the controller, it constructs a virtual spring
between the object’s original position and where it
wouldendupafterforcesareappliedtoit.
You can adjust spring tension and dampening.
Increasing the tension creates a tighter spring,
while increasing the dampening smo othes out
jitters in the motion. You can add external forces
like Gravity (page 2–73) and Wind (page 2–75) to
affect the motion, and also add additional objects
whose motions act as springs.
Note: You can also assign the Spr ing controller
to animated vertices in Track View: Open the
object ’s Master P o int Controller hierarchy, select
the vertices, and assign the Spring controller.
Interfa ce
When you assign a Spring controller to an object,
itsrolloutsautomaticallyappearintheMotion
panel. In addition, the rollouts open in a floating
dialog. If you close the dialog, you can reopen it by
right-clicking the track in the Motion panel Assig n
Controller rollout or in the Track View hierarchy
and choosing Properties, or clicking the Properties
button on the Track V iew toolbar.
Spring D yn am ics rollout