The particle operators on the Attributes tab allow you to set different types of attributes on the particle system. You can also set or create arbitrary attributes to particles using the Attribute POP. This lets you store custom per-particle information relevant to your simulation you can use later in expressions.
Directly set motion attributes
A more low-level way to affect particle motion than applying forces is to set the position and/or motion (velocity, acceleration) attributes of particles directly.
|To set particles'…||Use this operator|
The default rules that normally control the motion of particles based on their attributes will also be applied unless you turn them off with the Suppress Rule POP.