The effect that makes it possible for a mixed reality application to detect the spatial layout of a room and overlap or hide a virtual object based on its position is called occlusion. Occlusion allows virtual objects to be realistically blocked or hidden by real-world objects in the environment, creating a convincing integration of virtual and physical elements. This effect relies on spatial mapping or spatial understanding , where sensors such as depth cameras or LiDAR capture a 3D model of the environment, enabling the application to understand the position and dimensions of real- world surfaces and objects. By combining spatial mapping with occlusion, the application can accurately render virtual objects so they appear naturally placed and interact correctly with the physical space