Wouldn’t it be cool if non-player characters were more interactive? What if they were almost like real people?
With artificial intelligence developing at speed, developers are beginning to consider this as a real possibility. Well, I say ‘beginning’. In fact, AI has had a part to play in gaming for a while now. Perhaps one of the most well-known early examples is The Sims, which, in terms of its use of artificial intelligence, was actually way ahead of its time. Indeed, it has continued to use more and more sophisticated algorithms to drive character behaviour with each new version.
Lots of smaller, indie games have used AI in interesting ways to tell stories and build emotional engagement. Games like 2012’s Prom Week, developed by the University of California Santa Cruz, and the rather odd 2005 game, Facade, were experiments of some note in this field, of which Prom Weekin particular is a very interesting example. Prom Weekused AI to build on second-by-second social data, creating unique interactions between particular characters depending on their individual personalities. It’s well worth reading about, if AI in gaming is something that interests you.
As a natural progression, simultaneous to the developments we are seeing in the AI world at large, the possibilities for identity for non-player characters in videogames are growing exponentially. There’s just one question: do players really want AI-driven NPCs?
The main use for AI in videogames at the moment is to control and direct NPCs around the player, whether as enemy targets or non-player team members. Is there any need for emotional, lucid non-player characters if this is all they are expected to do?
Now and Next
Considering the complex and time-consuming nature of developing algorithms for this purpose, games developers need to be quite certain that doing so adds something significant to the gaming experience. It’s never really been a priority to use AI for characterisation in much depth for most big games developers, but having said that, the gaming space is changing – particularly with virtual reality technology promising a new era on the horizon.
With these changes in mind, it pays to assess what gamers are going to be looking for in these more immersive games of the future. We’ve already seen the design of games shift away from linear narrative adventures over the last five years or so, towards open-world games with greater capacity for emergent stories gaining in popularity.
The Times They Are A’ Changin’
Recognising that vacant NPCs who add nothing to the game open a chasm in the way of immersion, gamers have begun to express a preference for games where their existence in the game world is both registered and acknowledged by the NPCs within it. A good example is Middle Earth: Shadow of Mordor, developed by Monolith Productions. The game’s ‘Nemesis’ system meant that the computer-controlled enemies remembered previous fights with the player, which were then brought up in later encounters. Despite the relatively unsophisticated AI required to do this, players of the game reacted positively to the sense of permanence and agency the Nemesis system inspired.
Take this one step further, and imagine a version of, say, Grand Theft Auto, in which the missions don’t just come via the main narrative, but are also generated through countless conversations, drives, and desires of the NPC civilians that wander the streets of the game. What if each of those individuals was endowed with their own full character, personality, and backstory?
It seems like an insurmountable drain on memory resources by our current standards. But things are developing in this regard, too. Just think of how little memory there was in your old Commodore 64, then your SNES, your PS1, and now in your XBox One. Memory grows. There’s increasing amounts of space for such multi-faceted, multi-layered narratives powered by artificial intelligence.
James Ryan and the Expressive Intelligence Studio
At the University of California Santa Cruz, where Prom Weekoriginated, a team at the Expressive Intelligence Studio is doing some fascinating work on building an AI platform for gaming. Talk of the Town, so the platform is named, creates interactive experiences with (artificially) intelligent characters with their own ongoing personalities – their own beliefs, emotions, relationships, and memories. The project is headed by PhD student, James Ryan, and represents perhaps one of the most intense studies in the area of AI videogame characters.
Three different AI elements power the Talk of the Town platform. Firstly, natural language generation (NLG), which takes its cue from the dialogue manager’s decision about how to respond, and generates a line of appropriate dialogue. Then there’s the natural language understanding (NLU) system, the most complex element, which is being developed in collaboration with Adam Summerville. It converts what the player has said into a form for the dialogue manager to process. The dialogue manager, in turn, makes decisions on how the world should be changed as a result of the player’s words, along with how the NPC should respond. This is, of course, powered by neural networks.
James Ryan’s work is ultimately intriguing because of the dedication he is putting into getting AI to clearly understand and process input and generate a very human landscape of characters. Every action has a knock-on effect on other NPCs, the player’s experience, and the game world in general. He’s essentially trying to recreate AI-powered gaming worlds as close to human life as possible. Separate from Ryan’s work, Google DeepMind has just announced WaveNet, a tool that can generate highly convincing human speech.
We may be close to having AI characters in games that can actually speak their minds and affect the course of the game accordingly. It’ll start out rudimentary, of course, but will certainly grow more sophisticated as the technology evolves. If the gaming world changes in this direction, we can expect games that are so immersive that they can rival real life on many levels, particularly when realised through the medium of virtual reality. Does HBO’s series, Westworld, spring to mind, perchance?
For a thorough and fascinating article on the use of AI in videogames, we highly recommend this, by The Guardian: Video games where people matter? The strange future of emotional AI(October 2016).
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