Transform operators control particle position, rotation, scale, and angular velocity.
By default, particles are born, or emitted, from the Particle Flow icon. This topic uses the term emitter to refer to this icon. Use the Position Icon operator to control the initial placement of particles on the emitter. You can set the emitter to emit particles from its surface, volume, edges, vertices, or center. And, if you animate the emitter, you can cause its motion to be imparted to the particles it emits.
By default, particles are born, or emitted, from the Particle Flow icon. The Position Object operator lets you emit particles from any other object or objects in the scene instead. This topic uses the term emitter to refer to an object or objects used to emit particles with this operator. For example, use it to create a meteor's fiery trail.
The Rotation operator lets you set and animate particle orientation during an event, with optional random variation. You can apply orientation in any of five different matrices: two random and three explicit. For some options you can set a degree of random variation or divergence from the specified orientation.
The Spin operator gives an angular velocity to particles in an event, with optional random variation. Spin is applied once per event per particle, except when using the Speed Space Follow option; however, the settings can be animated.
The Scale operator lets you set and animate particle size during an event, with optional random variation. Options for how scaling and animation are applied give this operator a great deal of flexibility.