The action to perform when the Particle System is offscreen.
| Automatic | For looping effects, the simulation is paused when offscreen, and for one-shot effects, the simulation will continue playing. | 
| PauseAndCatchup | Pause the Particle System simulation when it is offscreen, and perform an extra simulation when the system comes back onscreen, creating the impression that it was never paused. | 
| Pause | Pause the Particle System simulation when it is offscreen. | 
| AlwaysSimulate | Continue simulating the Particle System when it is offscreen. |