Add HDR is one of these, new and sharper textures and more polygone models..and so on.
But the engine is exactly the same, but now its on its limit, when they add more the engine lose the think what i like, the *loving* good performance against other engines.
They have to write a source engine 2 cleaner and they will dont lose the performance thing, i think but dont know.
I let valve just do they stuff and i enjoy the games they release. But its my opinion, that they lose performance with stuff like these
