To connect the value of one attribute to another with an expression
Select the node with the attribute you want to edit and select Window > Animation Editors > Expression Editor. Click the attribute and type a MEL expression in the box at the bottom.
For example, to make the translateX value of pTorus1 always equal the translateY value of pCone2, type =pCone2.translateY in pTorus1’s translateX box. When you move the cone up and down in Y, the torus moves side-to-side in X.
You can create more complex expressions using multiple attributes and MEL’s math functions.
When you type an expression into a text box in the Attribute Editor or Channel Box and press , Maya then shows the computed value with an purple background. You can’t edit values that are the result of an expression. To edit the expression, use the Expression Editor.
Except where otherwise noted, this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License