xpFollowSurface General tab menu.
Checking this box activates xpFollowSurface.
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.
Drag the objects, that the particles are to move over, into this list.
The ‘pull’ is the strength with which the particle is pulled to the surface.