xpFlock mimics the behaviors and reactions of creatures within a flock, with particles interacting with each other and reacting to stimuli.

There are three tabs within xpFlock: Behaviors, Reactions and Avoidance.

xpFlock parameter settings.

Enabled

On, by default, this box can be unchecked to disable xpFlock.

Type

Set as Velocity, by default.

The alternative option is Force.

Velocity

Here, the xpFlock modifier takes complete control of the particle movement.

If you add another modifier, which also influences particle speed and direction (eg. xpTurbulence), you will find that it has little or no effect on the particle.

Force

In this mode, the change in velocity caused by this modifier contributes to, but does not control, the final particle velocity.

Adding a modifier (eg. xpWind or xpTurbulence) will also contribute to the final result.

This is the mode to use if you want to add some other kind of movement to the particle as well as the flocking effect.