GDC 2018: Bringing Life to the NPC's of Final Fantasy XV Using AI

Youichiro Miyake, Lead AI Researcher at Square Enix, took to the stage at GDC to talk about how he and his team brought the AI to life in Final Fantasy XV.

There is no denying that the AI, especially the companions of Noctis, are extremely reactive to the players choices. Hitting the breaks on the Regalia too hard will result in them all lurching forward and consequently complaining, swing a sword too close and they will dodge and scold Noctis for his clumsiness.

In order to govern these complex mechanics there are three main systems that determine how a NPC should react and respond to stimuli. The first being Meta AI which governs a NPC’s behaviour, the Character AI which is unique to that NPC will then react, finally the Animation AI then executes a visual response. When each system is working in unison it creates a unique reaction to that NPC from whatever stimuli it is being exposed to. This is a very dumbed down explanation of how the AI system works as there are layers upon layers of states and behaviours for every individual character and creature type.

There are many smart objects set up in the world of Final Fantasy XV for NPCs to interact with. A simple chair for example, one NPC may set themselves down in a relaxed pose while others may sit in a more formal manner. Smart objects are scattered around the world, in order to make it seem like the NPCs are actively living and engaging with their surroundings and not simply existing and walking from point A to point B.

By creating huge branching trees that each connect to various behaviours and responses the developers at Square Enix are able to create base behaviours and build on them. With various animation, behavioural, and specific character responses the AI system will be able to choose an appropriate response that is unique to that NPC in a real-time environment. The end result being a living and breathing world that is able to react on its own and to the players individual actions.

Final Fantasy XV is available on PlayStation 4, Xbox One, PC and the Pocket Edition is available on iOS and Android.