I will be getting the script when I've got the money, so in the mean time I decided to work through the setup you've got listed on this.. ran into a problem, and no, it's not the math ;) you've changed all the names of the nodes right? so, what is the incidence ramp? the tute is meaningless to me right now since you've not shown what nodes are in the ramp... (well what the first 2 in the chain are! - the rest I understand...)