emissionDuration
The duration, in seconds, over which the system spawns new particles. Animatable.
Declaration
var emissionDuration: CGFloat { get set }Discussion
The birthRate property determines the number of particles spawned during this duration. You can randomize the duration with the emissionDurationVariation property.
A duration of 0.0 specifies that all particles (the value of the birthRate property) spawn instantaneously. Use this duration to create randomized static effects in your scene. For example, by combining this option with the birthLocation and imageSequenceInitialFrameVariation properties, you can cover a plane with a variety of sprites, creating the appearance of a grassy field.
The default value is 1.0 seconds.
You can animate changes to this property’s value. See Animating SceneKit Content.