Perhaps this information posted by Stefan might be helpful:
- emitter.dropemitter, emitter.dropwateremitter - those work exactly like the emitter itself (e.g. you can edit emitter.dropemitter.particle) and are used for emitting particles once a particle drops on the ground (rain drops) or the lifetime is over (for fireworks) - once a particle is dropping the emitter is calling dropemitter.emitat() to produce the drops; if there is a dropwateremitter and the particle was dropping on water then it is using the dropwateremitter for the drop effect
Source:
http://forums.graalonline.com/forums...ad.php?t=62877