Thief 4 producer producer Stephane Roy has discusses the game's AI component with the PS Blog, stating that thanks to PS4 architecture, the team could push the immersion further than with PS3.
Elsewhere in the interview he discusses the DualShock 4 features in the game, such as how the light bar and touch pad will be used.
"For the DualShock 4, we use the light bar to reflect the light gem in the in-game UI, which indicates if Garrett is in the shadows or not," said Roy. "It creates a nice feeling when you play in the dark to see it illuminate or darken as you move through the environment. Additionally, the touch pad allows for better menu navigation and makes for a more intuitive way to perform various actions, like navigating the map or selecting weapons.
"What impressed us were not only the new features of the DualShock 4, but how the existing ones have been improved. The best example of that is the motion control, which is way more precise than before. You can use it to adjust your aiming with the bow and the level of accuracy we get with it is really impressive.
"The last thing is the Share button. We think it’s a great addition, especially for a game like Thief. We give a lot of freedom to the player, and we work really hard to create a systemic AI that will let the player find creative ways to play. Sharing those moments will showcase how they solved various situations — and we’re pretty sure that players will find ways that impress even us."
Rpy also touches upon the stealth mechanic, and how it pertains to the AI.
"When people think about the stealth in Thief, the first thing that comes to mind is the light and shadow," he said. "It is the core of our stealth, but it’s not only about that. We have a complex perception model that creates realistic situations. Being in the shadow reduces the visibility of the player, but the position of the player, their movement, and the distance all change how the AI perceives Garrett.
"We also model the sensors of the AI as realistically as possible. We distinguish between central vision and peripheral vision. This also is put forward by the way we use head tracking to make the AI look more believable when they react to something and look at the player.
"And there is also the sound that will attract and alert AI. Players can control the sound they emit by controlling their movement speed, but it’s also influenced by the surface they walk on.
Together, these elements create a realistic AI, but also an AI that’s fun to play with, that the player will be able to distract, evade, and try to outsmart."
Thief arrives on PC, PS3, PlayStation 4, Xbox 360 and Xbox One in February 2014.