animation
Adds or modifies an expression on a parameter without opening
the Expression Editor. If you want to open the Expression Editor
during execution, use the AddExpr
command instead.
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.
Note: This command uses output
arguments. C# and some scripting languages (such as JScript,
PerlScript and Python) don't support arguments passed by reference
so you need to use the best workaround for your situation:
For scripting languages this command returns an ISIVTCollection which you can
use to get the output arguments.
For C# you can use the XSIApplication.ExecuteCommand
method to call this command. ExecuteCommand packs the output
arguments into a C# System.Object containing an Array of the output arguments (see
Calling
Commands from C#).
SetExpr( [InputObj], [ExprStr], [ExprObj] ); |
| 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, "a.kine.global.posx = 3.5") |
| ExprObj | XSICollection | Returns a list of expression objects |
'
' This example sets an expression on a parameter using the SetExpr
' command and then uses the EditExpr command to open the Expression
' Editor to inspect the new expression.
'
' 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
SetExpr oDonut & ".kine.local.posy", _
"5*sin(" & oDonut & ".kine.local.posx * 15)"
' Now display the Expression Editor to see the results
EditExpr oDonut & ".kine.local.posy"
|