The Kill effect lets you determine when particles disappear.

Kill Properties

Parameter Description
Name Lets you rename the node.

An on/off switch using binary code. 1 = on, 0 = off.

Use Maximum Lifespan Makes particles disappear when they reach their maximum lifespan.
Kill Younger

To use this parameter, you must attach a function to this property because if you select this option at time 0, you will never see any particles. If you set Kill Younger to 10, at time 0, there will be no particles older than 10, so you will never see any particles.

It may be useful to have the particles animating over time, and at some point in time, you may want to kill all the younger particles. An example would be an animation where the particles change from blue to yellow. At every frame, new particles are generated, and the particles that already exist age. Then you would add an explosion that kills all particles younger than 10 frames. It would kill all the blue particles, leaving only the yellow particles.

Kill Younger Than

This is where you can animate the effect for Kill Younger.

Kill Older Makes particles disappear when they reach a certain level of maturity.
Kill Older Than Lets you set the age at which particles disappear.