One of the primary factors that separates an augmented reality device from a standard heads-up display such as Google Glass is dimensional depth perception. This can be created by either RGB cameras, infrared depth cameras, or both, depending on the level of accuracy you’re aiming for.
This understanding of depth allows our augmented reality devices to know the locations of usable surfaces. The result of this understanding is that we can place virtual objects on top of real objects in the real world. Or, at least, the functional illusion is created.
In the previous tutorial on building an AR… more
Source: ARCore 101: How to Create a Mobile AR Application in Unity, Part 4 (Enabling Surface Detection)
