xpFollowPath General tab menu.
Checking this box activates xpFollowPath.
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.
When in the Action-Controlled Mode setting, the modifier will only act on a particle when told to do so by an action.
These objects set out the path the particle stream will follow.
The stream will move to each object in the list in the order they are found there.
Each path object must have the following requirements: it must be a closed spline; it must be coplanar (all the points of the spline lie on the same plane); its axis must be centered within it; the profile must point along the Z-axis.