Use settings in the EnemyController script to adjust the visibility range. This area is divided into 2 parts - central vision (green) and peripheral (red). During the game, if a character enters this area, an enemy will see him, depending on the chosen behaviour model (read about it below).
If you mark the 'Use States' checkbox, an enemy will use Warning and Find states during the game.
If an enemy sees a character with the central vision, he will immediately attack him.
If the enemy sees (with the peripheral vision) or/and hears (read here about the character's noise) a character for a while or the character has shot him a few times, the enemy's warning state is activated and he will look for him.
If while searching the enemy has found the character, he'll activate the attack state.
If the enemy doesn't see or hear the character, he looks for him for а while again. And after that returns to waypoints.
If the 'Use States' feature isn't active an enemy will do the following:
If the enemy sees* or hears a character, he immediately attacks him.
If not, he immediately returns to waypoints.