Now that we understand how a basic vision detection that we can find in many action/adventure games works, we can move on and take a look at the advanced vision detection that can be found in stealth games. Let's take a deep look into the Metal Gear game and see how the AI characters have their vision developed.
If we take a look at this screenshot, we notice that the enemy AI cannot see the player, but the player is inside of the area where the enemy is well capable of seeing. So why doesn't the AI character turn to the player and start attacking him? Simply because the trigger area is set only to be in front of ...