Trapcode Particular
The Motion Path feature makes it possible to precisely control the path that a particle takes after being emitted. This is done by setting keyframes for a comp Light and naming the Light in a certain way.
This keyframed Light lets you control the path that particles travel after being born. Motion Path is useful when you need precise control of the particle path.
An example of a motion path with a keyframed Light.
The pop-up for Motion Path is the only Particular parameter you will set when creating a motion path. Each number corresponds to a number "X." That number is used in the name given to the comp Light that acts as the motion source.