In the comp there is a layer which is a 1920x1080 video of me moving around etc. I have cut myself out so I am on alpha and preComped the layer etc. I do not touch the bottom of the video.
Now what I want is for me to turn into particles and to rain down onto a floor layer. I have managed to make myself do this, and have set the particles to kill when they hit the floor. It works using both a grid emitter or a layer emitter and choosing the video of me as the layer.
However when I use Aux System and set it to Emit at a bounce event, the Aux system creates particles on the floor before any collision has taken place.
I suspect that there are 'invisible' particles that are being generated by the layer's alpha and that these particles are creating collision effects on the floor before any of the real particles hit it.
What can I do about this? How can I stop these extra particles?
Particular will emit particles from alpha channel but they will not be visible. Thats the problem you are facing while using alpha map in layer.
To solve this :
1. Go to Emitter>Layer Emitter>Layer Sampling.
2. Choose "Particle Birth Time" .