9

376 Chapter 12: Animation
Point group
Mass—The m ass of the object to which the Spring
controller is applied. Increasing the mass causes
the"bouncing"springmotiontobecomemore
exaggerated.
Drag—Ac ts as air friction on the spri ng motion. A
lowDragsettingresultsinagreater"bouncing"
effect, while a high Drag results in subdued
bouncing. Default=1. Range=0 to 10.
Springs group
Add springs to an object using the Spring
controller when you w ant the object to be affected
by the motion of other objects in your scene. This
effect ively creates v irtual springs b etween objects.
Add—Click this button, and then select one
or more objects whose motion relative to the
spring-controlled object will act as springs on that
object. To finish adding springs, click Add again,
right-click in a viewport, or press
Esc .
Remove—Removes highlighted spring objects
from the list.
Note: YoucannotremovetheSelfInfluencelist
entry, which is the spring-controlled object’s
influence on itself.
(Li st)—Listsallspringobjectsbyname,anddisplays
each object’s Tension and Dampening settings
separated by a slash (/). The spring-controlled
object’s influence on itself appears as Self
Influence, and cannot b e deleted. However, you
can effectively remove the object’s influence on
itself by setting Tension and Dampening to 0,
resulting in no motion.
To set Tension and Dampening for one or more
objects in the list, highlight them in the list and
then adjust the settings.
Tension—The "stiffness" of the virtua l spring
between the controlled object and the high lig hted
spring object(s).
Dampeni ng—Actsasamultiplierofaninternal
factor that determ ines how quickly the object
comes to rest.
With the Self Influence spring, changing
DampeninghasthesameeffectaschangingDrag.
With other springs, Dampening affects only the
move ment caused by that spring.
Internally, the dampening value is proportional
to the tension, so as you increase the tension and
makethesolutionmorestiff,thedampeningis
increased to maintain system stability.
Relative/Absolute—With Relative chosen, changing
the Tension and Dampening settings causes the
new settings to be added to the existing values.
With Absolute chosen, the new settings replace the
existing values.
Forces Limits and Precision rollout
External Forces group
Add—Click this button, and then select one or
more space w arps in the Forces category that are to