9

Limit Controller 335
Note:
All animation layer names persist in the
Layer Name list even after you delete their host
object. Resetting the scene clears the list.
[controller type]—Determines the cont roller t ype
to assign to each track within the animation layer.
•
Duplicate the Active Controller Type—The new
layer’scontrollertypebecomesthesameasthe
one from the active layer, on a per-track basis.
For example, if a track in the active layer has a
Noise controller, adding a new layer copies that
controller type.
•
Use Default Controller Type—When chosen,
the new layer’s controller does not take into
account the active layer’s controller type and
instead uses the origina l t rack’s type.
Limi t Controll er
Maintoolbar>CurveEditor(Open)>Highlightatrack
in the Track View hierarchy. > Track V iew menu bar >
Controller menu > Assign > Float Limit
Graph Edito rs > Track View - Curve Editor > Highl ight a
track in the Track View hierarchy. > Track View menu bar
> Controller menu > Assign > Float Limit
The Limit controller lets you specify upper
and lower limits to available controller values,
thus restricting the potent ial value range of the
controlledtrack. Forexample,inacharacter
rig you could use this to restrict rotation on
finger joints so the fingers can’t bend backward.
Basically, once a track is limited, and the limit is
active, you can’t set a value for the track beyond the
limit. You can apply a Limit controller to any other
type of controller; the limited controller (that is,
the original controller) then appears as a child of
the Limit controller in the Track View hierarchy.
Because the Limit controller doesn’t change the
original controller, you can easily switch back
and forth between the original and the limited
animation by toggling the limits. But if you collapse
(page 2–522) the Limit controller, the result is the
limited animation, and the orig inal animation is
no longer available.
Use of the Limit controller makes it faster to set
up and create animation. It eliminates the need
for expressions or scripts to do the same thing,
this improving the eas e with which you c an set up
automation in hierarchies and rigs, creating effects
such as avoiding collision, FK joint limits, etc.
For example, a Technical Director might want to
assign limits to float values that animators will
adjust to ma ke posing easier, enforce standards, or
prevent inconsistencies and mistakes. A TD could
use limits for:
• light intensity
•fingerrotation
• position extents for sliding drawers
•camerafield-of-view
• limiting patch resolution to that supported by
the game engine
Character riggers can use limits to create com plex
relationships or shortcuts in rigs. Examples
include:
• Wire wrist-twist bones to t he rotation of the
hand, but limit the rotation of the wrist-twist or
hand to stop short of any flipping that might
occur.
• Prevent unnatural translation of a spline IK
helper by causing limit values for its local
position tracks to react to the angle or distance
of the helper from surrounding helpers.
• React to when IK is disabled, and match the
limits of the solver i n FK.
• Limit the position of the IK chain swivel-angle
target for the k nee so that it can never go behind
the chara cter. That is, the target is linked to
character’s root.