The animation amount on the X-axis.

The animation amount can also be set using the Vector property, and other properties in different subclasses.

This property has different defaults, means different things in different subclasses:

• For Move, this property denotes points, unless distorted by scaling. Default is 0.
• For Rotate, this property denotes radians. Default is 0.
• For Scale, this property denotes a scale factor, where 1 is unchanged scale. Default is 1.