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, the enemy will see him, depending on the chosen behavior model (read about it below).
If you set the 'Use States' checkbox the 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 the attack state will be activated.
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 the enemy will do the following:
If the enemy sees* or hears the character, he immediately attacks him.
If not, he immediately returns to waypoints.