Love the new water shader, I've been playing about with trying to get it to simulate glass, doable but very dependant to the individual scene. Effectively the glass/water shader has no back face to reset its effect. The transparent effect will carry on untill it hits an object, the back of the room, the nearest line of sight mountain or the background object. If I look through a piece of real glass it has a depth at which its not glass any more, ie the light rays have passed through the glass object and out the other side. Looks like the water shader has no "other side". Indeed if a glass plane object is imported with only a single polygon and made double sided it refracts the image behind it twice. If a real world glass pain object is imported (ie it has a thickness of say 5mm) then the light is refracted a total of four times. There make for some interesting images but not very usefull.
I think the issue here is partly due to the fact that I'm trying to cheat a shader into doing something it was'nt designed for and partly due the fact that within Terragens implementation of obj's single sided that side is always facing the camera, therefore there is no way for terragen to streighten out a refracted ray.
I have also noticed that every time I stack more than two layers of glass over eachother the program freezes or crashes, easily repeatable.
Also notice how in the image below the grid llines are not refracted but the object is and the refraction seems to have a magnification effect.
Happy rendering
Richard