I suggest that you Google bagginsbill and glass see what comes up. He has done some extensive work on glass shaders for both Firefly and Superfly with analysis comments. Given the nature of this topic, I wouldn't be surprised if he chimes in. Now a one-fits-all glass shader might be a tall order to fill unless we're talking background objects as prop fillers to complete a scene. But using glass objects in fore- and mid-ground renders might require a different approach. It's a shame that everything posted at both SmithMicro and RuntimeDNA has completely disappeared from the internet.