Setup and animation with deformers
You can set keys on any of deformer’s keyable attributes (or channels). Keys can be set in the Channel Box, the Time Slider, the Graph Editor, the Dope Sheet, or by using the Maya Embedded Language (MEL™) commands.
When setting up characters, you can create attributes that drive deformer attributes by adding new attributes, and then defining relationships between the new attributes and the deformer attributes.
Add
new attributes from the Add Attribute window
(
Modify > Add Attribute). Define
relationships between attributes with the Connection Editor (
Window > General Editors >
Connection Editor),
the Set Driven Key window (
Animate > Set Driven Key > Set > 
), or
by writing expressions in the Expression Editor (
Window > Animation Editors
> Expression Editor).
This guide refers to channels as keyable attributes that are displayed in the Channel Box. You can use the Channel Control editor to specify that a node’s animatable (potentially keyable) attributes that are not in the Channel Box by default be displayed as channels in the Channel Box. Note that it’s possible to put non-animatable (and therefore non-keyable) attributes into the Channel Box, but in general all channels in the Channel Box are keyable attributes.
For more information on Maya’s animation features, refer to the Animation guide.