9

432 Chapter 12: Animation
If you change the animation of the second hand at
frame 75, it affects the position of the hand relative
to the ball at the time of the link (frame 50). This
change in relative position affects the ball over
all frames where it is linked to the second hand.
Therefore, as you change the position of the hand
at fr ame 75, the child’s position will also change,
possibly in a counter-intuitive way. However,
when playing back the animation the above three
rules w ill hold true.
Adjusting Object Tr ansfor ms
You use the features on the Adjust Transform (page
2–489) rollout to transform objects after they have
been linked without transforming descendents,
and to reset an object’s tr ansform.
Tr ans for ming Pa rent Obj ects
You might discover, after linking a number of
objects, that you need to move, rotate, or scale a
parentobjectbutyoudonotwanttoaffectthe
object’s descendents. You c an transform a parent
object without affecting its descendents by clicking
Don’tAffectChildrenontheAdjustTransform
rollout of the Hierarchy panel.
R esetti ng a n Obj ect’ s Or ienta tion and
Scale
ClicktheTransformbuttonintheResetgroupto
rotate an object’s pivot to match its parent’s local
coordinate system. D escendents of the object are
not affected.
Resetting an Object’s Scale Only
Click the Scale button in the Reset g roup to set the
current sc ale value as the selected object’s base
scale value. All following scale transforms are then
appliedusingthebasescalevalueasanabsolute
local scale of 100%.
Consider a sphere with a radius of 20 units and a
linked child object:
1. Use Uniform Sc ale to scale the sphere to 200%.
Thesphereanditschildbecometwiceasbig.
Scale Transform Type-In reports an Absolute
Local Scale of 200% and the object’s creation
parameters report a radius of 20 units. The t r ue
radius of the sphere is 200% of 20 units, or 40
units.
2. Select the sphere and click Reset Scale. The
sphere and its child remain the same size.
Here’s what has happened:
The 200% scale has been absorbed by the
sphere as its original s tate. The sphere has a
true radius of 40 units, Creat ion Parameters
report a radius of 20 units, and absolute local
scale is 100%.
The sphere’s child object accepts a local scale of
200% so it does not change in size.
Resetting the scale of an object can lead to
confusion because the object’s t rue size, absolute
local scale, and creation parameters no longer
match up.
Using the R eset Transform Utility
You can also reset the orientation and scale of an
object by clicking Reset XForm (page 1–438) on
the Utilities panel (page 3–778). Reset XForm takes
therotationandscaletransformsofanobjectand
places them in an XForm m odifier on the modifier
stack.
Considerthesamesphereasbeforewitharadius
of 20 units and a linked child object:
1. Use Uniform Sc ale to scale the sphere to 200%.
Thesphereanditschildbecometwiceas
big. The Scale Transform Type-In reports an
Absolute Lo cal scale of 200% and Creation
Parameters report a radius of 20 units. The true
radius of the sphere is 200% of 20 units, or 40
units.