There is diffrence between Force and ParticleAlter class. ParticleAlter affects ParticleEmitter when Force affects spawned particles which will touch it.
Is active or not.
How change particle velocity:
- FORCE_Addictive - new force will be add to particle velocity
- FORCE_Multiply - new force will multiply particle velocity
- FORCE_Replace - new force will replace particle velocity
New particle speed.
New particle speed variance.