9

Spring 729
Par ent Sp ace—
At this sub-object level, you
can select and move the constraint’s second
attachment point. If the spring is two-bodied, then
this is the point relative to the parent where the
spring is attached to it. When you assign a paren t
object to the Spring, the Parent Space attachment
point is set to the parent object’s pivot point. If
you alter the position of the attachment point, it
maintains its new position relative to the parent. If
thespringissingle-bodied,thentheParentSpace’s
attachment point represents the point in the world
where the spring is attached.
Properties rollout
Par ent—When on, the Spring has two bodies and
youcandesignateanobjecttobetheparentbody.
Whenoff,theSpringissingle-bodiedandthe
point occupied by the Parent Space sub-object is
the parent.
Youassigntheparentobjectbyclickingthisbutton
andthenselectingarigidbodyfromanyviewport.
Thereafter the button d isplays the name of the
parent body.
Child—Displays the name of the second rigid body
attached to the Spring. You assign the child object
by clicking this button and then selecting a rigid
body from any viewport.
Align S paces To—Use these options to align the
bodies’ local constraint spaces. You can find out
more about each option in the Working With
Constraint Spaces (page 2–726) section.
Lock Rel a ti ve Tra n sf or m —When on, the relative
transform between the child and parent constraint
spaces is locked: If you move either space in the
viewport, the other space moves along with it.
Stiffness—The strength of the spring; governs the
force the spring applies to each attached body for
each unit difference between its current length and
its rest length. Values greater than or equal to 0.0
are valid. Default=10.0.
Rest Length—The spring applies forces to the
attached objects in an attempt to reach t his length.
You can specify a figure in world units for this
value, or you can use the Set button. The spring’s
rest length is displayed in t he viewports as the
length of the displayed line b etween the two
small box markers. The large box markers are the
objects’ attachment points.
Set—Click this button to set the spring’s rest length
to the current distance b e tween the two objects’
attachment points.
Dampi ng—Determines how quickly the oscillation
of the spring settles down. It governs the forces
applied to t he connected bodies due to the
relative velocities of their connection points. Valid