Adds an expression to one or more parameters and then opens the Expression Editor. This is a combination command (ie., it's the equivalent of using SetExpr and then EditExpr). You can disable it from appearing by setting the DisableAutoInspect parameter to True.

An expression is a string of characters that may include object and parameter names, mathematical operators, and tokens representing functions or constants. For example, to constrain object A's Y rotation to object B's X translation, you would set an expression on A.kine.local.roty consisting of the string B.kine.local.posx.

An expression is a mathematical formula that you can use to control any parameter that can be animated, such as translation, rotation, scaling, material, or texture. You can create almost any connection you like between parameters, from simple "A = B" relationships to very complex ones using predefined variables, standard math functions, random number generators, and more.

For more information on expressions, see the Animation guide.

Scripting Syntax

AddExpr( [InputObj], [ExprStr], [DisableAutoInspect] );


Parameter Type Description
InputObj String List of parameters (for example "cone*/kine.local.pos").

Default Value: Currently selected and marked parameters

ExprStr String An expression.

Default Value: Current parameter value (for example, " = 3.5")

DisableAutoInspect Boolean True to prevent the Expression Editor from appearing automatically.

Default Value: False


VBScript Example

' This example sets an expression on a parameter using the AddExpr command
' without inspecting the new expression in the Expression Editor.
' Create the object on which to set the expression
set oDonut = CreatePrim( "Torus", "NurbsSurface" )
' Make sure the last frame will be set to 100
SetValue "PlayControl.Out", 100
' Set a key frame at frame 1, with XPos = -30
SaveKey oDonut & ".kine.local.posx", 1, -30
' Set another key frame at frame 100, with XPos = 30
SaveKey oDonut & ".kine.local.posx", 100, 30
' Animate the YPos parameter with an expression
AddExpr oDonut & ".kine.local.posy", _
                "5*sin(" & oDonut & ".kine.local.posx * 15)", True

See Also

Parameter.AddExpression EditExpr RemoveAnimation RemoveAllAnimation SetExpr