Coming back to Unreal, as you would expect, there is a subsystem of the AI Framework that implements AI Perception. Once again, you are free to implement your own system, especially if you have particular needs…
With Sensing and Perception, we are collocating at a lower level than Decision-Making (like Behavior Trees and EQS). In fact, there is no decision to take, no place to select, but just a passage/flow of information.
If the Sensing System perceives something "interesting" (we will define what this means later), then it notifies the AI controller, which will decide what to do about the received stimuli (which is its perception, in Unreal terminology).
Therefore, in this chapter, we will focus on how to properly set up the Sensing System so that our AI can perceive, but we won't deal with what to do once we have received...