The Perfect Organism: The AI of Alien: Isolation

Created on 2022-03-07T19:32:16-06:00

Alien has its own AI system that controls just the alien.
AI systems are pre-designed behavior trees.
Subtrees can be conditionally locked so the AI cannot do those things until a trigger has unlocked them. This simulates the AI “learning” to do new things through the game.
Alien is made to appear more chaotic by having it path based not on optimal global pathfinding but using more localized means like taking a random path or preferring paths that it can readily see.
Alien uses a job system where tasks are put in a list and it completes them on priority; may cancel other jobs or do a couple of jobs in order.
Director tries to manage stress level of player; sends alien closer to player if they have been away for too long or further if they have been nearby for too long.
Pathing is deliberately suboptimal (based on “vision” of alien) since the backtracking can be sold as patrolling or double-checking an area.