8

Reference Coordinate System 425
The World coordinate system is always fixed.
Par ent—Usesthecoordinatesystemoftheparent
of the selected object. If the object is not linked to
a specific object, it’s a child of the world, and the
parent co ordinate system is the same as the world
coordinate system.
Example of a Parent object coordinate system
Local —Usesthecoordinatesystemoftheselected
object. An object’s loc al coordinate system is
carried by its
pivot point (page 3–1089) .Youcan
adjust the position and orientation of the local
coordinate system, relative to its object, using the
options on the Hierarchy command panel.
When Local is active, the Use Transform Center
button is inactive and a ll transforms use the loca l
axis as the center of transformation. In a selection
set of several objects, each uses its ow n center for
the transform.
Local uses an individual coordinate system for each object.
Gimbal—TheGimbalcoordinatesystemismeant
to be used w ith the
Euler XYZ Rotation controller
(page 2–312)
.ItissimilartoLocal,butitsthree
rotation axes are not necessarily orthogonal to
each other.
WhenyourotateaboutasingleaxiswiththeLocal
and Parent coordinate systems, this can change
two or three of the Euler XYZ tr acks. The Gimbal
coordinate system avoids this problem: Euler XYZ
rotation about one axis changes only that axis’s
track. This makes function curve editing easier.
Also, absolute t ransform type-in with Gimbal
coordinates uses the same Euler angle values as
the animation tracks (as opposed to Euler angles
relative to the World or Parent coordinate system,
asthosecoordinatesystemsrequire).
For mov e and scale transforms, Gimbal
coordinatesarethesameasParentcoordinates.
When the object does not have an Euler XYZ
Rotation controller assigned, Gimbal rotat ion is
the same as Parent rotation.
The Euler XYZ controller can be the active
controllerinaListcontroller,too.
Gri d—Usesthecoordinatesystemoftheactive
grid.