Maya has special driven keys that link one attribute value to another. In regular animation keys, an attribute has values keyed to times in the Time Slider. For a driven key, an attribute has values keyed to the value of a driving attribute.
A change in a driver attribute alters the value of the driven attribute. For instance, you can set driven keys to make a door open when a person walks in front of the door.
An attribute can be driven by multiple attributes. For instance, you can make a muscle bulge when an elbow rotates. You can make the muscle bulge even more when the wrist rotates.
When you set driven keys, Maya creates a Graph Editor curve that shows the relationship between the linked attributes. For regular animation keys, the Graph Editor’s vertical axis lists attribute values, and the horizontal axis lists animation time values.
For driven keys, the Graph Editor’s vertical axis lists driven attribute values, and the horizontal axis lists driver attribute values. For each attribute value of the driver, the curve shows the associated value of the driven attribute. You can edit the curve to alter the relationship. You can’t animate driven attributes with regular keyframes.
The Time Slider is not involved in a driven key relationship and displays no red markers for the keys. Playing or scrubbing the animation alters the value of a driven attribute only if you animate the value of the driving attribute over time. See Set Driven Keys overview.
You can use two or more driver attributes to control a single driven attribute. You can also drive more than one driven attribute with the same driver attribute. The technique is similar to linking two attributes, with the following exceptions:
