| animator | The Animator evaluating this state machine. |
| animatorStateInfo | Information about the state being evaluated. |
| layerIndex | The current layer being evaluated. |
Invoked on each update frame except for the first and last frame. Implement this message to execute custom logic on a state by state basis.
OnStateUpdate is invoked every frame for the currently evaluated state, as well the next state and the interrupted state if applicable.
Note: OnStateUpdate may be invoked multiple times on the same state if that state is synchronized on multiple layers.