Using Affects options to specify particles (PB only)

Many Particle Playground properties include a group of settings under the heading Affects that specify which particles are affected by an option. You can include or exclude particles based on their properties.


Using the Older/Younger Than option to make particles older than a certain age (left) change color (right)

To specify the particles that are affected by an option:

Under the property name, click the right-facing triangle next to Affects, and specify the following settings:

Particles From

Choose the particle generator or combination of particle generators whose particles you want to be affected by the current option.

Selection Map

Choose a layer map that influences which particles are affected by the current option (see About layer maps (PB only)). Selection is based on the brightness, or luminance, of each pixel in the layer, so a particle is affected more or less as it passes over layer map pixels of different brightness. By default, a property affects a particle 100% where the brightness value of a corresponding layer map pixel is 255 (white), and has no effect where the brightness value of a corresponding layer map pixel is 0 (black).

Note: The simulation space is not bounded by the dimensions of the layer to which Particle Playground is applied. You may need to use a selection map that is larger than the Playground layer so that dots that are not visible are still affected by Selection Map options.

Characters

Choose a text field containing the characters you want to be affected by the current option. This option applies only if you are using text characters as the particle type. For example, if you're setting up the Gravity property and you define a text field containing the characters A, E, I, O, and U, the current option affects those characters only. (The Characters option is case-sensitive.) To define the text fields, click Options at the top of the Particle Playground effect controls section, type text in Selection Text 1, Selection Text 2, and Selection Text 3 as necessary, and click OK. (The characters you type here are also case-sensitive.) Once you've created selection text, choose the selection from the Characters menu under Affects. For more information, see Replacing default particles with text (PB only).

Older/Younger Than

Specify the age threshold, in seconds, above or below which you want a particle to be affected by the current option. Specify positive values to affect older particles, or negative values to specify younger particles. For example, if you set this option to 10, all particles older than 10 seconds use the new value. As soon as a particle reaches 10 seconds, it changes to the new value.

Age Feather

Specify the age range in seconds within which the Older/Younger Than value is feathered, or softened. Feathering creates a gradual, rather than abrupt, change. For example, if you set Older/Younger Than to 10 and Age Feather to 4, about 20% of particles will start changing when they're 8 seconds old, 50% will change when they're 10 seconds old (the Older/Younger Than value), and the remainder will change by the time they're 12 seconds old.