The Object tab menu in xpGravity
Checking this box activates xpGravity.
Animation to demonstrate the effect of enabling xpGravity, with all particles immediately affected by the force of gravity.
Set at Independent, by default.
You can change this to Action-Controlled.
In this mode, particles will be affected if they come into the field of effect of the modifier.
In this animation, with Mode set to Independent, the particles are becoming affected by the xpGravity modifier once they enter the field of effect.