How would I create a reflective glass texture?

I know about the existence of func_reflective glass, however I don’t need something as detailed as that and I need something more flexible than that entity anyways. I’ve seen reflective glass being used in maps like Littletown so I know its certainly possible, how would I go about doing it though?

I know I would probably have to use the following parameters for my material file

but what about everything else?

This is the effect I am shooting for, though the windows I would like to create would have a little more transparency.

Did you try cubemaps with big resolution? Also ask hiyougami, glass is one of his fetishes

People are integrating ray-tracing into Source now if you could get your hands on that

What? Where? That’s not really something you can add without changing the engine code.