Trapcode Particular
The Particle group contains all the settings for the particle's appearance. Controls include Size, Opacity, Color and how these properties vary over the particle's lifespan.

Life controls how long the particles live, measured in seconds. High values give a long particle life, low values give a short particle life. When keyframed, the particle’s life is determined by the value at the frame when it is born. This value is grayed out for Form behaviors.
Life Random sets the randomness for Life, as measured in a percentage. At set to zero, all particles will have the same lifespan, and die all at once. When set above zero, the particles get slightly different lifespans. Higher values means the randomness is higher, and the particles have more variation in length of life. This is useful for creating natural looking effects like trails. This value is grayed out for Form behaviors.
Determines what kind of particle is emitted. Controls may be enabled or disabled depending upon the Particle Type selected. Review the Particle Type page for more information.
Depending upon the Particle Type you have chosen, you may get a different set of controls available:
Sprite: Click the Choose Sprite… button to bring up a panel of images available to use when Sprite is selected as the Particle Type. You can also import your own Sprite using the Add New Sprite… button in the top right of the box. Imported images will be added in a “Custom” folder at the bottom.
Right-click on a model’s thumbnail image to either:
Sprite Controls : options available to modify a Sprite. See the Particle Type page for details.
Sphere/Cloudlet/Streaklet Feather : Controls the softness of the following Particle Types: Sphere, Glow Sphere, Cloudlet and Streaklet. Grayed out for the other Types. Low Feather values give the look of sharp circles. High Feather values give a more organic, smooth look.
Left to right, Sphere Feather set low and high. Particle Type is Glow Sphere.
Change properties of the particles to control how they will interact with their Environment, such as Mass and Air Resistance. Review the Particle Physics page for more information.
Size sets the size of the particles. High values create a larger particle, low values a smaller particle. When keyframed, the particle’s size is determined by the value at the frame when it is born.
Size Random
Size Random sets the randomness for Size, as a percentage. Higher values mean the randomness is higher, and the particles have more variation in size.
Size over
Controls how the particle size varies over the particle's life or X,Y,Z and Radial axes for Form behaviors.
The Rotation group rotates the particles independently on the X, Y and Z axes. You can even give the particles a random rotation so they rotate in different directions. Read more on the Rotation Group page.
The ratio of the particles width to its height. Default is a square ratio of 1 to 1 (1.0). Increasing this value will make your particles wider, values under 1.0 make them thinner.
Opacity sets the transparency level of the particles. At 100%, particles are completely opaque, at 0% they are completely transparent. When keyframed, the particle’s opacity is determined by the value at the frame when it is born.
Opacity Random
Opacity Random sets the randomness for Opacity, as a percentage. Higher values mean the randomness is higher, and the particles have more variation in transparency.
Opacity over
Controls how the particle opacity varies over the particle's life or X,Y,Z and Radial axes for Form behaviors.
Set Color is the method for setting the particle's color. There are eight options. Each option activates other color-related Particle parameters.
Color
Color controls the particle's color. Active when Set Color is set to At Start. There is no numeric value for Color. When keyframed, the particle’s color is determined by the value at the frame when it is born.
Color Random
Color Random sets the randomness for Color, as a percentage. Higher values mean the randomness is higher, and the particles have more variation in color.
Color Randomness at 0, 50, 100. Color is white.
Color from Parent
When the emitter type is set to Emit from Parent System, you can set whether the color of the particles is controlled by their parent particle. This is a percentage that says how much the parent color is mixed with the color from Set Color. At the default 100%, the color comes entirely from the parent. At 0%, the color is entirely driven by the Set Color parameter above.
Color Gradient
Controls how the particle color varies over the particle's life or over the X, Y, Z and Radially axes for Form behaviors. Active when the Set Color popup is set to Color Over Life, Over X, Y, Z, Radially, or Random from Gradient.
The Color Over Life gradient has three control areas for setting the color on the gradient, choosing a preset and randomizing or reversing the gradient.
The Blend Mode controls how particles are composited together. There are six options.
Turn on Unmult when your Sprite texture has been pre-multiplied and is getting an unwanted dark edge from the black background.
Controls how the particle transfer mode varies over the particle's life. Active when Normal Add over Life or Normal Screen over Life is selected for Blend Mode. Read more on the Using Curves page.
Blend Mode Over Life is useful when transforming one particle volume into another set of particles. For example, let's say that you are creating flames that turn into smoke. While the particle is in the flame, the Transfer Mode should be add or screen, since flames have additive properties. Later on, as the particles becomes smoke, the Transfer Mode should be Normal since smoke has obscuring properties.
Only active when particle type is Glow Sphere or Star. Glow Size is the relative size for the glow compared to the particle. Opacity, Feather and Transfer Mode controls the look of the glow. Read more on the Glow group page.
These controls become enabled when Streaklet is the chosen Particle Type. Read more on the Streaklet group page.