Animation controllers are plug-ins that are responsible for managing animation. The most common controllers are interpolating or keyframe controllers. Other controller types are position/rotate/scale, mathematical expressions, and fractal noise. Constraints are a subset of controllers. Controllers derive from the Control class.
Audio controller - \samples\controllers\audcont
An audio amplitude controller.
Block controller - \samples\controllers\block
A block controller is a list controller that allows you to combine several tracks from multiple objects over a range of time, and group them as 'blocks'. These Blocks are then used to re-create the animation anywhere in time. Blocks can be added, removed, scaled, moved graphically in Track View, and saved. Blocks can represent either absolute or relative animation.
Boolean controller - \samples\controllers\boolean
The Boolean controller is similar to the On/Off controller. By default, it is assigned to tracks (such as an object's Visibility track) that provide only binary on and off control.
Reaction controller - \samples\controllers\reactor
A controller plug-in that reacts to changes in other controllers
Path Constraint - \samples\controllers\path_cnstnt.cpp
A path constraint restricts an object's movement along a spline or at an averaged distance between multiple splines.
Spring controller - \samples\controllers\spring
A mass-spring position controller
Wave controller - \samples\controllers\wavecntrl
The waveform controller is a float controller that provides regular, periodic waveforms. Created originally to control blinking lights, it can be used on any float value.