  X-ray vision, a technique that allows users to see through walls and other
obstacles, is a popular technique for Augmented Reality (AR) and Mixed Reality
(MR). In this paper, we demonstrate a dynamic X-ray vision window that is
rendered in real-time based on the user's current position and changes with
movement in the physical environment. Moreover, the location and transparency
of the window are also dynamically rendered based on the user's eye gaze. We
build this X-ray vision window for a current state-of-the-art MR Head-Mounted
Device (HMD) -- HoloLens 2 by integrating several different features: scene
understanding, eye tracking, and clipping primitive.
