8

Adjusting Object Transforms 413
Link to Wor l d
You can also link an object to the world using the
Link to World button. This will keep the object
stationary without t he use of a dummy object. Just
click Link to World and the world is aut omatically
entered as a Target.
Key Modes
You can choose between three different key modes ,
which determine how keyframes are wr itten on
the linked objects as part of the link constraint.
Theseoptionsprovidethefollowing:
No K ey M ode—No keys are created any of the
objects involved. No keys will be visible in the
track bar.
Key Nodes—Sets keys for some of the objects.
Chil d applies keys to the child object only. Pare nts
applies keys to both parents and the child object.
K ey Entire Hierar chy—This applies keyframes to
the chosen nodes and their entire hierarchies.
Chil d keys the chosen object and the nodes in
its hierarchy up to the world. Pa r e nts keys both
parents and the child and all three hierarchies up
to the world.
Side E ffects of the L ink Constrai nt
The Link constraint works to keep a child object
from jumping position at the time when the link
changes from one parent to another parent.
Considering the previous example, the following
should hold true:
• During frames 0 to 50 the ball remains constant
relative to the first hand.
• Duringframes50to100theballremains
constant relative to the second hand.
• At frame 50, the time when link cont rol
changes, the ball does not jump.
If you change the animation of the second hand at
frame 75, it affects the position of the hand relat ive
totheballatthetimeofthelink(frame50).This
change in relative position affects the ball over
all f r ames 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-intuit ive way. However,
when playing back the animation the above three
rules w ill hold true.
Adjusting Object Transforms
You use the features on the Adjust Transform (page
2–472)
rollout to transform objects after they have
been linked without tr ansforming descendents,
and to reset an object’s tr ansform.
Transforming Pare nt Objec ts
You might discover, after linking a number of
objects, that you need to move, rotate, or scale a
parentobjectbutyoudonotwanttoaffectthe
object’s descendents. You can transform a parent
object without affecting its descendents by clicking
Don’tAffectChildrenontheAdjustTransform
rollout of the Hierarchy panel.
R eset tin g an Obj ect ’ s Or ient at ion a nd
Scale
ClicktheTransformbuttonintheResetgroupto
rotate an object’s pivot to match its parent’s loca l
coordinate system. Descendents of the object are
not affec ted .
Resetting a n Object ’s S cale Only
Click the Scale button in the Reset group to set the
current scale value as the selected object’s base
scale value. All following scale transforms are then
appliedusingthebasescalevalueasanabsolute
local scale of 100%.