In case you missed it, be sure to watch my light shaft tutorial.
In this video I show you step by step on how you can setup a light shaft material with edge fade, camera fade and more. It should be enough for you to use or improve upon for your usage. I go through some of these nodes: eye adaption, time, speed, gradient, texcoordinate, breakout2component, power, depth fade, scene depth, substract, pixel depth, divide, camera depth, fresnel and so on.
