@EventMobil
Sorry, I had no idea you'd even replied to me, I just spotted it through following a link here.

Thanks for the heads-up, looks like I'll have to break my vow and take a look at those shader systems after all.  I've been avoiding both Baggins' and Snarly's scripts intentionally to make it harder on myself, but I suppose using them might even help me grasp things better, so what the hell.

Not in the mood for it right now as my mind is on other things, but I'll definitely take a look sooner rather than later, cheers!