Editing expressions

 
 
 

To edit an expression after you’ve created it and closed the window, you must know how to find the expression in the Expression Editor. The next steps show how to find and edit the expression. Specifically, you’ll change the expression to alter how quickly the scaleY value changes.

To edit the expression

  1. To display the Expression Editor again, select Window > Animation Editors > Expression Editor.
  2. To find the expression, make sure the Ball is selected. In the Attributes list of the Expression Editor, select scaleY, the attribute controlled by the expression.

    If you don’t see the scaleY attribute, scroll through the Attributes list as necessary. You can also use the Select Filter menu option to customize how you search for your expressions within the Expression Editor.

    The expression you created previously appears in the expression text field:

    Ball.scaleY = time + 1;
    
  3. Change the expression to this:
    Ball.scaleY = time/5 + 1;
    

    By dividing time by 5, you’ll make the Y scaling increase one-fifth as fast as with the previous version of the expression.

    Note that you can use the keyboard commands Ctrl-c (Windows and Linux) or Control-c (Mac OS X), Ctrl-x or Control-x, and Ctrl-v or Control-v to copy, cut, and paste text in the Expression Editor and elsewhere in Maya.

  4. Click Edit to update the modified expression.

    Clicking Edit does the same action as clicking Create. Create exists only for new expressions. Edit replaces Create when you display an existing expression.

  5. Play the animation to see the results of the new expression.

    The sphere scales at a slower rate than before.

  6. Stop the animation and go to the start time.
  7. At this point and in subsequent steps, save the scene if you think you’ll want to examine it at a later date.