I have a CAEmitterLayer animated along a bezierPath and my CEEMitterCell particles are made with an partly transparent gaussed-circle.png. these particles have a lifetime of 0.3 which leads to a small tail of my animated CAEmitterLayer-Particles. I need to have the tail becoming smaller at the end and have the cells fade out to alpha = 0 over lifetime. I tried different combinations of parameter settings and I din't get it to work. I just made the end of the tail fatter, looking ugly wrong. please, what are the necessary parameter settings here? Is this even possible with CAEmitterCells?
You should be able to achieve this usin alpha and size of the cells. Look at the scaleSpeed. You could also look at alternative renderMode values in your emitter layer