Behavioural modelling is an important part of NPC development for games. Should emotive modelling be part of that development?
Consider your favourite video game. If it contains AI controlled agents how individualistic are they and their behaviours, and how might you set about improving them?
The purpose of AI, by definition, is creating technology that can “to perform tasks normally requiring human intelligence” (Oxford Dictionaries, 2017). So when games designers are creating non-player characters (NPCs) the focus is on the emulation of human behaviour. At this point, game designers are getting pretty good at it, NPCs can move, talk, and over-all behave like human beings on a relatively superficial level. But in order to truly capture the human condition, I believe it should be vital to include emotive modelling in the development process, as all decisions we make are based on varying degrees of emotion. If we take into account that “emotions are an essential part of the believability of embodied characters that interact with humans” (Bartneck, 2017), if a designers goal is to evoke an emotional response towards their NPC, then emotion is vital to the equation.
Take The Last of Us, for example (again, I know). With a game that relies so strongly on a character driven plot, its essential to the experience that the NPCs are tangible, believable characters. In the first half of the game, focusing on NPCs Ellie and Tess, both are standout, individual characters who’s constant dialogue makes their personalities distinct. I personally connected with Ellie immediately, but it took me a while to connect to Tess, because her character is written in such a way that makes her stand-offish, sharp tongued and a little petty. Their emotional modelling is fantastic, however. They are both real, believable characters that the player acknowledges as separate entities, and proves the point – at least in my personal opinion – that if a designers goal is to evoke an emotional response towards their AI, emotive modelling is key to that experience.
The Last of Us 2013, Joel and Tess arguing
That being said, there’s a lot about The Last of Us AIs that aren’t perfect. There are plenty of moments, in my experience, in which I have been caught yelling at my TV screen because one of the NPCs has followed me into a dangerous territory that I was sneaking through and just started firing shots at the NPC enemies. Moments like this undermine the intuition and innovation of putting a stealth mechanic in the game to begin with – if an uncontrollable entity is going to compromise your position the game becomes somewhat frustrating to play. It’s a good example of when a programmed “humanistic” behaviour goes awry: the player does want the NPC to follow them, but they don’t want to be tripping over said NPC every time they turn around. In this specific instance it might be helpful to have the AIs recognise that the character was in stealth-mode, activated by a specific button, and lag behind just a touch more instead of charging into the fight guns blazing.
The Last of Us stealth mechanic
So despite AIs and NPCs having come so far in terms of behaving like humans both physically and emotionally, there is still a way to go in creating a truly believable AIs that blend so seamlessly into their surroundings you could forget they were there.
Reference list:
Anon, (2017) Oxford Dictionary, 3rd ed
Bartneck, C. (2017) The Relationship Between Emotion Models and Artificial Intelligence
Helpful links:
https://en.oxforddictionaries.com/definition/artificial_intelligence