The total number of particles this zone will emit before the Emitter transfers control over to the next zone in its emission zone list.
By default this is -1, meaning it will never pass over from this
zone to another one. You can call the ParticleEmitter.setEmitZone
method to change it, or set this value to something else via the
config, or directly at runtime.
A value of 1 would mean the zones rotate in order, but it can be set to any integer value.