Emitter group
The Emitter is the place where particles are born and given their initial velocity and direction. It's a big group of controls. You can set important characteristics such as emitter shape, style and position. The emitter group also sets the initial velocity of the particles and determines how many particles are emitted.

The full Emitter control list.

Particles/sec

This is the main control for the number of particles created by the plug-in each second. For example, a value of 100 particles per second means that Particular generates 5 to 6 new particles every frame depending on your project format (NTSC or PAL video). Low values generate fewer particles and are normally faster to render. High values create lots of particles and can be slow to render. This value can be keyframed so that particle emission varies over time.

The value can also be modified by the Particles/sec Modifier when the Light(s) Emitter Type is active.

Left to right, Particles/sec at 100 and 600.

Emitter Type

Sets the shape and function of the Emitter. There are seven types. See the Emitter Types page.

Position XY & Position Z

The position in 3D space where particles are born. These values can be keyframed over time to create trails and similar effects.

- Set Position X to move left or right around the X-axis.
- Set Position Y to move upwards or downwards around the Y-axis.
- Set Position Z to move closer to or farther from the camera around the Z-axis.

Position XY is moved to the upper left (left), and center of comp (right).

Position XY is moved to the center right

Position Z at a value of 300 (left) and 0 (right).

Position Z at a value of -600.

Position Subframe

Position Subframe smoothes out the movement of the particles where the emitter position is moving very quickly. In Particular 2.0, the default interpolation is linear, which means each frame is interpreted linearly. This is identical to the behavior of particles in version 1.x. If you have a slow-moving emitter, than this mode works fine because the particles are moving so fast that everything looks smooth. But if you want the emitter position to move quickly, this is a problem because you will see only a linear path. There are four options.

The Position Subframe pop-up

- By default, Position Subframe is set to Linear.
- 10x Linear creates a new position particle at 10 subframe points in time, and then samples the position for the particle from the resulting points. This results in a more accurate position for fast-moving particles and typically is fine for everything but the fastest-moving particles.
- Set to 10x Smooth if you need the movement to distribute the points more evenly along the curve calculated at the same 10 subframe times as the 10x linear mode. This mode can give a slightly smoother motion along the path but renders at nearly the same same speed as the 10x Linear mode.
- Exact (slow) will accurately calculate the position of every particle based on the velocity of the emitter position. We don't recommend using Exact unless you have a very few particles in the scene because this will slow down the rendering of the particle simulation considerably, especially if you are using a large number of particles in the Particles/sec control.

Below is an illustration of a particle emitter moving across the frame in just 3 frames. This high velocity will result in inaccurate particle positions unless a subframe mode other than Linear is chosen in the pop-up menu.

The Linear (default) particle position. Notice how the particles do not adhere to the motion path.

The 10x Linear option calculates a much closer approximation to the ideal path of the particles, but still show some straight line sections.

The 10x Smooth option calculates a smooth approximation to the path, close enough to be useful in 99% of all cases.

The Exact (Slow) option calculates a perfect path but is 10x slower to render. This is only necessary in rare cases.

Direction

This pop-up controls the direction in which particles begin movement. There are five settings. The default is set to be a random movement.

| Uniform Initial direction is completely random. This is the default setting. |  |  | Directional Emit in a specific direction. Use Direction Spread and X, Y, Z Rotation to control the beam.
| Bi-Directional Emits in two opposed directions at the same time. Use Direction Spread and X, Y, Z Rotation to control the beams. |  |  | Disc Emits in a plane so particles form a disc over time.
| Outwards Emits outwards from the center of the Emitter. For a Point Emitter, this is the same as Uniform, therefore the Grid Emitter is shown here. |  |  |

Direction Spread

Controls the spread of the particle beam for certain Direction Types.

- Used with these Direction Types: Directional, Bi-directional, Disc and Outwards.
- Disabled for Uniform emitters.
- Disabled for Light Emitters. Read more about Light Emitters.

Left to right, Direction Spread set low and high. The Direction control is set to Directional.

Left to right, Direction Spread set low and high. Direction is set to Disc.

X,Y and Z Rotation

Rotates the Emitter around the X, Y and Z axes.

- Set X Rotation to rotate forward or backwards around the X axis.
- Set Y Rotation to rotate to the left or right around the Y axis.
- Set Z Rotation to rotate around the Z axis.

Velocity

Velocity sets the initial velocity of newborn particles. Higher values make the particles move quickly. Lower values make the particles move slowly. When set to 0, no particles are emitted. This control is sometimes referred to as 'Initial Velocity' in the Trapcode Particular documentation.

Velocity Random

Adds randomness to the initial velocity of newborn particles. This means that the particles are born with varying initial velocity. Higher values add more randomness to Velocity. This control is affected by Random Seed.

Velocity from Motion

Lets the particles take on, or 'inherit', the Velocity from the Emitter. For this control to have any effect, the Emitter must be in motion.

- Negative values give the feeling of a 'jet' spray or engine. The particles spray opposite to how the Emitter moves, and they appear to push the Emitter forward.
- Positive values give the effect of something that is shedding particles as it moves, like stars from a magic wand.
- Positive values can also make it look as if particles are getting caught in the draft of the moving Emitter.
- A value of 0 means the Emitter motion has no effect on the particles' initial Velocity.

Emitter Size X, Y and Z

These three controls set the size of the emission area of some Emitter Types.

- This control is enabled for Box, Sphere, Grid and Light emitters.
- For Point emitters, this control is disabled.
- For Layer and Layer Grid emitters, only the Z control is enabled since their X and Y size is controlled by the size of the layer specified in the Layer Source pop-up.

Here is how Size works.

- Set Size X for the emission area to become wider or narrower. Use a value that matches the layer width if you want the emitter to fill the frame width.
- Set Size Y for the emission area to become taller or shorter. Use a value that matches the layer height if you want the emitter to fill the frame width.
- Set Size Z for the emission area to become deeper or more shallow. Use a higher value if you want to create a large field of particles like snow falling across an area.

Left to right, all Sizes at 50, Size X at 600.

Left to right, Size Y at 600, Size Z at 600.

Particles/sec Modifier

This control lets you emit particles from lights. Only active when the Light(s) emitter is the Emitter Type. See Light Emitter page for details.

Layer Emitter group

This group of controls lets you emit particles from layers. Only active when the Layer emitter is the Emitter Type. See Layer Emitter group page for details.

Grid Emitter group (previously in the Options panel in version 1.5)

This group of controls lets you emit particles on a 2D or 3D grid. Only active when the Grid or Layer Grid emitter is the Emitter Type. See Grid Emitter group page for details.

Emission Extras (previously in the Options panel in version 1.5)

This small subsection has two controls that are used less frequently.

Pre Run. This control is used to pre-run the system so that particles can be visible at the first frame. The pre-run value is a percentage value where 0% is no pre-run. At a value of 0, the simulation essentially starts at the first frame where no particles have been emitted. A value of 100 translates to a 100% completion of the emission of particles on the first frame. At 100%, all particles that should be emitted at the first frame will appear based on Emitter controls such as Velocity and the particle life.

Periodicity Rnd. This control is used to emit particles at random intervals. It is only useful when using a directional emitter with Direction Spread at 0.

Random Seed (previously in the Options panel in Particular 1.5)

The Random Seed controls all randomness controls in the effect, such as Velocity Random. It is useful when you wish to duplicating an effect and add a slight variation of particle positions, et cetera.