Particle systems let you create sophisticated effects involving large numbers of automatically animated objects.
You can add a premade particle system to your composition from the Library, or you can create your own custom particle effects using nearly any image layer or group in your project, including still images, shapes, text, and movies.
Particle systems consist of two basic elements:
Particle emitter: A special type of effect applied to a layer, causing the layer to multiply and animate according to the parameters you set in the Inspector.
Particle cell: The image layer that’s multiplied and animated by the particle emitter.
The emitter and cells have separate sets of parameters that control the particle system’s behavior. If you imagine that a garden hose is a particle system, the nozzle acts as the emitter, while the water represents the flow of particles. Changing the parameters of the emitter changes the shape from which the particles are emitted as well as their direction. Changing the cell’s parameters affects each particle.
Each particle created in the Canvas is essentially a duplicate of the cell, and is animated according to the parameters of that particle system over its lifetime.
The layer you use as a particle system’s cell determines the appearance of that particle system. Particle systems can contain multiple cells (image layers), resulting in the release of several types of particles from a single emitter. Many of the most sophisticated particle presets in the Particle Emitters library are constructed in this way.