This was the original idea, as of Beta 5 and Beta 6 these are functional and become transparent up close, but at distance become opaque. One improvement I wanted to make since V2 was to have window textures on the exterior correlate to actual windows on the interior. The main challenge with introducing transparent windows becomes optimization, as everything inside that room when viewed from the outside (and vice versa looking from the inside) has to be rendered. With the way it's done now, once you get a certain view distance away from the window, it becomes opaque and stops rendering whatever's behind it