Particle emitter is a wrapper for SPE particle system.
SPE is a threejs based particle emitter engine.
Documentation for SPE particle engine can be found here https://squarefeet.github.io/ShaderParticleEngine/docs/api/index.html
A dynamic particle emmiter ignores the position in its transform and applies it directly to the emitter origin.
Emitter has attributes that can be used to controll the particle system
Particle group instance.
Texture attached to the group of this particle emitter.