private Particle CreateParticle()
{
// Fast creation (don't use superclass since emitter will init)
Particle newParticle = freeParticles[0];
freeParticles.RemoveAt(0);
// add the billboard to the active list
activeParticles.Add(newParticle);
newParticle.NotifyOwner(this);
return(newParticle);
}