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Recently, a movie based on video games, "Free Guy" (translated as "Out of Control Player" in Chinese), starring Ryan Reynolds, the actor who played "Deadpool", was released in North America and China.

The whole film is light-hearted and funny, with exquisite special effects. It performed well in the summer season, and achieved good box office results and praise from many audiences and game players around the world.

When NPC becomes the protagonist

In the story of "Freeman", the protagonist Guy lives in a place called Free City, where there are two completely different types of people.

A group of people are called "people wearing sunglasses". They commit crimes, robberies and massacres in this city every day. They have different styles, different personalities, and cool and powerful equipment.

These people wearing glasses seem to be the masters of this city.

There is another type of people in the city, just like the protagonist Guy. They don't even have a decent name. They often have a fixed look, an unchanging personality, and live an unchanging life.

Guy is a bank clerk. Every day when he arrives at the bank, different "men in sunglasses" will come to rob. Everyone is used to it and seems to be cooperating with the "men in sunglasses" to complete this task.

All this changed dramatically after Guy met a mysterious woman wearing sunglasses. He seemed to have awakened, and after waking up one day, Guy wanted to take charge of his own life and understand the truth of this city.

Finally, he broke his daily routine, snatched a pair of sunglasses from the "man wearing sunglasses", and finally saw the world behind the sunglasses.

With the help of the mysterious woman, Guy finally realizedIt turns out that Liberty City is a large-scale online open world game. The reason why people with glasses are so different from them is that people with glasses are all players of this game.

Guy himself is just an ordinary NPC in the game, and everything he is familiar with is just the background and quest line of this game.

The reason why Guy was able to awaken his consciousness is because the original development team of the game had done a lot of artificial intelligence design and development on the NPCs, and these characteristics were triggered by the appearance of the mysterious woman.

It is these AI technologies that have transformed Guy from an ordinary game NPC into an elusive "out-of-control player" who is not controlled by the game development team.

How will the AI-enabled Guy rewrite his own destiny, and how will it influence the outcome of human players? You are welcome to go to the cinema to watch the full movie.

Game AI progress, not bad?!

In movies, NPCs with AI capabilities can rewrite their own plots, but in reality, NPCs are never the protagonists in games, players are.

As indispensable tools, NPCs exist naturally to help players succeed, to help players transition through plots, fight monsters and level up, and complete tasks, even if they have to sacrifice themselves or get beaten up for the players.

With the rapid development of gaming technology, players are no longer satisfied with NPCs with fixed routines, and game manufacturers are also racking their brains to improve the gaming experience.

 1. Use GTP-3 Modbox 

Modbox, a VR sandbox game editor developed by Canadian game studio Alientrap, was the first to allow players to experience AI NPCs.

Modbox support allows players to create their own worlds, games or VR experiences in VR and PC through the various tools it provides, and explore them with other players.

Does it already have the flavor of the metaverse?

The following conversation is a video clip posted on a social networking site by Lee Vermeulen, lead developer at Modbox. It is a real-time voice conversation between a player and a hot dog stand NPC after the player encounters one on the road.

​Modbox's AI NPC is created by combining technologies such as Windows speech recognition, OpenAI's GTP-3, and Replica's natural speech synthesis.

Finally, the conversation between players and NPCs is no longer based on fixed options, but is vividly expressed through real-time voice interaction and body movements.

 2. Intelligent wild monsters seem a bit mentally retarded 

As a dark horse in the gaming industry this year, "Valheim: Valheim" once dominated the Steam weekly sales chart and won eight consecutive championships.

This is an exploration survival game inspired by Viking culture. Shortly after its release, the maximum number of concurrent online users on Steam reached 360,000.It's hard to imagine that such a well-made and complexly designed game was completed by a development team of only five people.

Although this powerful production team has developed a very unique AI system for the game, the NPC monsters in the game are not always smart.

The most common bug is that when a player character appears in front of a monster, the monster should identify the player as the top priority character and attack the player without hesitation.

But sometimes when there are buildings near the player, these monsters will suddenly act stupid.

Some AI monsters are at a loss and stand there, while some AI monsters will waver between players and buildings, not knowing who to attack first.

 3. Gameplay, or FPS NPC advanced  

For FPS (first-person shooter) type games, the personification of NPCs is the core goal of AI research. In the game, victory in evenly matched battles will bring a sense of fairness and accomplishment.

First-person games such as FPS are often based on three-dimensional game scenes, which are more similar to the real world. Anthropomorphic AI trained in such a virtual environment can better reflect the performance of humans in real environments.

The first step is to give the AI full game capabilities, that is, the ability to complete any task in the game.Taking PUBG as an example, the player’s goal is to “survive to the end”. Key tasks include exploring the area, collecting weapons and equipment, entering the safe zone and fighting the enemy.

By adopting the reinforcement learning method, end-to-end training can be completed from 0 to 1, and highly intelligent AI can be achieved through observation design, model design, action space design and reward mechanism.

After mastering the full game capabilities, the second step is to improve the anthropomorphic performance of the AI.First, two sets of data need to be input, one is high-quality human desensitized data, and the other is the aforementioned AI NPC data trained by reinforcement learning methods.Then, the data of the two are separated by the discriminator, and a set of intrinsic reward mechanisms are output to motivate AI to continuously move closer to human behavior.

Game AI makes small characters become big heroes

The tool-like nature of NPCs in games sometimes makes players ignore their existence. But in the movie "Player", the NPC played by Ryan Reynolds, who was transformed and upgraded by AI, has more comprehensive cognitive abilities and the ability to associate and think.

Not only did Guy use his own AI capabilities to break through fixed personalities and default actions, gaining the ability to innovate and break through game design, he also infected NPCs in other games, helping them unlock the AI power within their bodies.

The game creates an exquisite and beautiful fantasy for players, equips them into different characters, and gives them different abilities and goals. Because of this, players are willing to immerse themselves in such a dream.

Now, through artificial intelligence and reinforcement learning, the game development team has applied these dream-making abilities to every character in the game to create a more complete and realistic dream for players.

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