In a previous video of the Expressions 101 series (part 2), you learnt about the animation channel hierarchy and this enabled you to drive the animation of one object off another.

This was referred to as the "Controller" Technique.

In part 5 of the Expressions 101 series, you are going to take this technique one step further and combine multiple animation curves into a single curve that will than drive your primary animation.

This is possible through combining multiple expression curves or even combining an expression with a key-framed animation.

There are plenty cases where you would use this.

For example, controlling the height of a bouncing ball, Controlling the intensity of a camera shake or perhaps controlling the randomness of an object in a motion graphic.