Unity has a rich and sophisticated animation system called Mecanim. Mecanim provides:
Unity’s animation system is based on the concept of Animation Clips, which contain information about how certain objects should change their position, rotation, or other properties over time. Each clip can be thought of as a single linear recording. Animation clips from external sources are created by artists or animators with 3rd party tools such as Max or Maya, or come from motion capture studios or other sources.
Animation Clips are then organised into a structured flowchart-like system called an Animator Controller. The Animator Controller acts as a “State Machine” which keeps track of which clip should currently be playing, and when the animations should change or blend together.
A very simple Animator Controller might only contain one or two clips, for example to control a powerup spinning and bouncing, or to animate a door opening and closing at the correct time. A more advanced Animator Controller might contain dozens of humanoid animations for all the main character’s actions, and might blend between multiple clips at the same time to provide a fluid motion as the player moves around the scene.
Unity’s Animation system also has numerous special features for handling humanoid characters which give you the ability to retarget humanoid animation from any source (Eg. motion capture, the asset store, or some other third-party animation library) to your own character model, as well as adjusting muscle definitions. These special features are enabled by Unity’s Avatar system, where humanoid characters are mapped to a common internal format.
Each of these pieces - the Animation Clips, the Animator Controller, and the Avatar, are brought together on a GameObject via the Animator Component. This component has a reference to an Animator Controller, and (if required) the Avatar for this model. The Animator Controller, in turn, contains the references to the Animation Clips it uses.
The above diagram shows the following:
Unity’s animation system (Known as “Mecanim”) comes with a lot of concepts and terminology. If at any point, you need to find out what something means, go to our Animation Glossary.
While Mecanim is recommended for use in most situations, Unity has retained its legacy animation system which existed before Unity 4. You may need to use when working with older content created before Unity 4. For information on the Legacy animation system, see this section
Unity intends to phase out the Legacy animation system over time for all cases by merging the workflows into Mecanim.