Line of sight is the way in which the AI may, or not, see things based on:

-Range/distance of vision. How much physical distance you can see your target. If your target is further away, then you can no longer see it.

-Angle of Vision: What opening does the vision have.

-Obstacles: If there is any object/obstacle that prevents us from seeing the target.

It is designed to be highly customizable and very easy to integrate with other projects.

Documentation