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Expression Controller 315
Expression Controller
Maintoolbar>CurveEditor(Open)>Selectatrackinthe
Track View hierarchy. > Track View menu bar > Controller
menu > Assign > Expression
Graph Editors > Track View – Curve Editor > Select a track
in the Track View hierarchy. > Track View menu bar >
Controller menu > Assign > Expression
Animation menu > Position or Scale controller >
Expression
Interface (page 2–317) Procedures (page 2–315)
With the Expression controller you can use
mathematical expressions to control the following
animation aspects:
• Object p arameters, such as length, width, and
height
• Transform and modifier values, such as an
object’s position coordinates
You can constrain values by basing them on the
controller values of other objects in the scene
An expression is a mathematical function that
returns a va lue. 3ds Max evaluates the expression
once for each frame of an animation, generating
values that can change from f rame to frame.
You create and manage expression controllers in
Tr ack View — D ope Sheet (page 2–489) .Youcan
assign expressions to the following kinds of scene
elements:
Scene element Controller
Creation parameters Any numeric creation
parameter
Scene element Controller
Transforms
Position[X,Y,Z]
XRotation
YRotation
ZRotation
Scale [X%, Y%, Z%]
Modifiers Any numeric modifier
parameter (including
creation parameters)
Materials Colors [R, G, B]
Any numeric material
parameter
Note: Expression controllers can work only with
the i ndividual XYZ components of Euler rotation.
You c an’t assign an expression to TCB rotation or
other kinds of rotation controllers.
See also
Expression Techniques (page 1–141)
Expression Control ler Techniques (page 2–318)
Trigonometric Functions (page 1–145)
Vec tors (page 1–146)
Procedures
To assign a constant value to a variable:
1.
Highlight the variable name in the Scalars or
Ve c t o r s l i s t .
2. Click Assign to Constant.
3. In the dialog, enter the new value of the
constant, and then click OK.
To assign a controller to a variable:
1.
Highlight the variable name in the Scalars or
Ve c t o r s l i s t .
2. Click Assign to Controller.
The Track View Pick subdialog is displayed,
showing the track hierarchy. The display in the
dialog is similar to the Track View hierarchy.