This is a demo of the Magic Window for HoloLens. In order to obtain this effect you simply need to utilize the HoloToolkit-Unity package found at:

https://github.com/Microsoft/HoloToolkit-Unity

Under the Utilities folder is a Tests folder and inside of that is a WindowOcclusion.unity scene. The actual window object is made up of the 4 cubes that make the frame you see and then 4 more cubes that are large and one each side of the frame. There is one on top, one on bottom, one on the left and one on the right. These cubes have a material that have the WindowOcclusion shader applied. This occludes any item that is behind it. So the window can be seen through but the “walls” around the window are transparent to the user, but are really keeping the main scene from view.

This demo is a quick response to the #hololens_challenge found at
https://medium.com/@hololens_challenge/hololens-challenge-4-through-the-looking-glass-99d566c2b1b0#.y1j19wcv1

You should try it out. You could definitely create more complex meshes to surround the window, but the premise is the same. This is the same type of effect used in RoboRaid when you shoot your walls to expose pipes and cables, etc.

Enjoy the video!