OptionalemitterPer-frame callback supplying the emitter world transform. Most demos pin the emitter to a fixed position; non-trivial uses (e.g. a particle attached to a moving object) read live state here.
OptionalnameStable name for engine lookup. Defaults to the class name; pass an override when registering multiple ParticleFeatures (e.g. block-break + explosion particles in the same scene).
Initial particle graph config. Use ParticleFeature.setConfig to swap configs at runtime (the feature destroys the previous pass and builds a fresh one).