Introduction to: NWC603COM – Using AI in Computer Games Assignment 2

Introduction to: NWC603COM – Using AI in Computer Games Assignment 2


Artificial intelligence (AI) in the gaming world today has become the sole reason games become either a massive success, or flop, and become a failed enterprise. AI can make or break a game, and the methods and techniques used by developers to give us the illusion that AI is intelligent is what we will be investigating in this blog. (Introduction to: NWC603COM – Using AI in Computer Games Assignment 1)

In this assignment I will be following up from assignment 1, now I have researched the AI techniques used in computer games, I will be first thinking of a simple game idea and then I will talk about the AI algorithms\techniques applied and how they will used in-game. For the techniques that I wont be applying to my game idea, I will be talking about how they are used in other games we play today. I have decided to fulfil this task ahead by creating a blog, I feel I can give you the reader, a much more personal opinion of my views of AI in Computer Games.


AI Techniques I will be reviewing:

1.1 My Game Idea
1.2 Algorithm & Hacks
1.3 Tactics & Strategy's
1.4 A*
1.5 State Machine
1.6 Patrol

2.1 Elements not used in my game
2.2 Boids Flocking
2.3 Fuzzy Logic & Decision Tree's
2.4 Q-Learning & Artificial Neural Networks
2.5 Heuristics

3.1 Conclusion
3.2 References

Introduction to: NWC603COM – Assignment Brief

NWC603COM Assignment Two 

AI and Games

Learning Outcomes to be assessed in this assignment

Evaluate suitable core AI elements and their suitability to different game contexts and then generate ideas and concepts to use AI elements in a computer game.. 

Portfolio - Documentation and oral examination (viva)

This portfolio represents 20% of the module mark.

Task

Blog your game ideas and in particular how AI can be used within it. Describe the various elements you are doing and how they apply to this concept you are proposing.

So in basic terms talk about all the elements and how they could be used in a game and then for the main element focus on it in more detail pls.

This document / blog should also contain information on what type of game you are planning for the assignment and what techniques you deem suitable.

Viva

In a short viva you will be asked about your game concept and the various AI elements. Number of questions about the previous weeks’ topics, aimed at testing your understanding as well as to explain your game design ideas, described on your document / blog.

3.1 Conclusion

Conclusion

So in my second assignment, I was first tasked to come up with a game idea, one that include one or more algorithmic elements of gaming AI, I then had to create a blog which covered the algorithmic elements to be used in my game. I was then tasked to research the remaining elements that I don't plan on using in my game but to discuss where and how they are used in today's games. The AI element in section 1 which covers the methods used in my game idea are: Algorithm & Hacks, Tactics & Strategy's, A*, State Machine and finally Patrol. The elements discussed not used in my game where that of: Boids Flocking, Fuzzy Logic & Decision Tree's, Q-Learning & Artificial Neural Networks and Heuristics. My intent was to not only find out in more depth what many elements I will be using in my game idea but understand how they work with the great games I play everyday.

I'd like to just refer back to my game idea post (1.1 My Game Idea)

My idea is to have a very basic layout of lets say two rooms, my player character will start in room A and I will have a zombie AI character in room B. The goal is so that the zombie character will first walk around room B on a patrol walking between two points in the room and as the player character then enters the room B, the zombie will then trigger, chase down and kill the player character.

From the above plan of my game idea, I would like to walk through very quickly where I have succeeded in my task of applying these AI elements to my zombies.

Algorithm & Hacks - So the basic rules that have been tasked to the zombies is that of algorithm, from patrolling between two points to the attack on the player character. the hack comes in when the player can predictability of the AI, also the very similar code applied to both zombies (lazy code).
Tactics & Strategy's - When the AI's move in to attach the player, they will work together to surround and kill the player character.
A* - This element will come into play when the zombies leave their position to chase down the player, in the way will be a rock so the AI will need to determine the best route for moving around the rock and getting to the player character.
State Machine - Used when the character player enters the room and the zombie AI will go from a wander state (patrolling between two points) to a attack state and chasing down the player.
Patrol - Will be used right in the beginning when the zombies are patrolling between point 1 and point 2 in room B.

I can honestly say that from this blog, I have learnt that even in the simplest of games, there are many AI elements that take place. I've been again able to research these aspects of AI and the roles they partake in the games that are enjoyed by millions. To finish I would like to say that all elements begin with an algorithm, the basic rule setting technique is applied in all AI's in games and without that function, we wont have developed the amazing AI elements we have today to make games so realistic.

3.2 References

References

(1) Company Facts, Unity - Game Engine, 2017, https://unity3d.com/public-relations

(2) W Gallear, AI and Games, Waynes HE Blog, 2017, https://hnchnddegree.blogspot.co.uk/2017/10/ai-and-games.html7

(3) A Champandard, RTS to FPS: Using Strategy AI in Action Games, AI Game Dev, Oct 5th 2007, http://aigamedev.com/open/article/rts-fps/

(4) A Champandard, RTS to FPS: Using Strategy AI in Action Games, AI Game Dev, Oct 5th 2007, http://aigamedev.com/open/article/rts-fps/

(5) J Grzyb, Artificial Intelligence in Games, Code Project, Aug 28th 2013, https://www.codeproject.com/Articles/14840/Artificial-Intelligence-in-Games

(6) J Weibull, Visualising game theory with boids flocking, YouTube, June 1st 2015,
https://youtu.be/Tz3CgSwUREQ

(7) Unity Documentaiton, Making an Agent Patrol Between a Set of Points, Jan 2017
https://docs.unity3d.com/Manual/nav-AgentPatrol.html

(8) C Jay, Drivatars explained, YouTube, Nov 26th 2013, https://www.youtube.com/watch?v=MpMi93bBZOE

1.1 My Game Idea

My Game Idea

The software I will be using to create my game will be Unity - Game Engine, "Unity Technologies offers a platform for creating beautiful and engaging 2D, 3D, VR, and AR games and apps. A powerful graphics engine and full-featured editor enable you to realize your creative vision fast, and deliver your content to virtually any media or device. You can easily connect to your audiences on PCs, consoles, the web, mobile devices, home entertainment systems, embedded systems, or head-mounted displays."(1) Unity is a massively used product in industry around the world, over 34% of the worlds top games are made using the Unity - Game Engine. PlayStation, Apple IOS, Android, Microsoft are just some of the many platforms Unity supports, because of its world known name and mass use in the industry today, I have chosen to use Unity as my platform for creating my game, I feel it is important to learn how Unity works and gain experience using one of the worlds most used engines.

So my game... My idea is to have a very basic layout of lets say two rooms, my player character will start in room A and I will have a zombie AI character in room B. The goal is so that the zombie character will first walk around room B on a patrol walking between two points in the room and as the player character then enters the room B, the zombie will then trigger, chase down and kill the player character. Below is my layout of the game and how I want it to look:

So as you can see from my floor plan that the player character will start in room A and head towards room B, room B is being guarded by two zombie AI's which is currently patrolling between two points. When the player character enters room B the AI's vision path will detect the player character, chase him down and kill him. 

The elements of gaming AI I will be using to make this game with be that of algorithm (Using AI in Computer Games - Assignment 1, 1.1 Algorithms), because I am setting the AI character's basic rules to follow. By telling them to walk between two points and then hunt down the player character and kill him when noticed in game triggering an instance, simple commands telling the AI what to do. I will also be linking this to a hack algorithm (Using AI in Computer Games - Assignment 1, 1.3 Hacks) in gaming AI, in this instance the hack will be applied to both zombie AI's because the code will be the same, the code is so basic that the player character will know what the zombies will do even before it has happened.

Another element applied will be that of tactics and strategy, (Using AI in Computer Games - Assignment 1, 5.1 Tactics & Strategy's) now there will not be much but the zombie AI's will have a strategy which will be to surround and attack the player character. 

State Machine will be used in my game to refer to the state of the zombie AI's (Using AI in Computer Games - Assignment 1, 4.1 State Machines) this could be either evade, attack, wander an find aid, the two I will be covering will be wander and attack, two very important elements which will be linked in my game.

The final element is a pathfinding concept, the A* heuristic cost function algorithm will be used in the zombie AI. The reason the A* will be used is because Dijkstra can find the most ideal paths from one node to all other nodes on the graph, but A* finds only one good path between two nodes. And that is what I'm looking for, there will only be one objective for the zombie which will be to walk between two points and the attack the player character.

So there we go, I now have my game idea, what engine I will be working in, the layout for the game and finally the algorithm elements that I will be using to make the game work. In the next 1.2, 1.3 and 1.4 I will be discussing the three elements used in greater detail. In section 2 I will be covering the other elements used in AI in gaming and see how I could or could have applied them into my game along with how they are used in the games we play today.

1.2 Algorithm and Hack

Algorithm

So where will the algorithm element fit into my game? Well I now have my game planned out as you can see in 1.1 Game Idea, the main element of the zombie AI will be that of algorithm. The first action of the zombies will be to walk between two points in room B, like on a patrol. The algorithm aspect will be basic set of rules that I am giving the zombie AI characters, you can see my post on algorithms from my previous post (Introduction to: NWC603COM – Using AI in Computer Games Assignment 1 - 1.1 Algorithm).

("Simple set of rules of the form of an algorithm to simulate real world behaviour. If we look at games form the past such as pac-man. If we look at the behaviour of the ghosts. They move around the mase is a seemingly random motion then once the player gets close they simply chase the player") (2)

So lets compare with from what Gallear is quoting to my game, well he says that algorithms are used to simulate real world behaviour, I would agree to him to an extent, yes the zombies will be moving like humans, putting one leg forward and then the other but being zombies... they don't exist so it cant be exactly like real world. Gallear refers to the game pacman and how the ghost AI responds to the player character, on my game I want to emulate the same intention but whereas in pacman, when the player character gets to close then the AI will attack, in my game I plan to have the AI chase down the player character immediately when the player character enters room B. So lets look into the role of the zombie AI's:

Zombie A - Will be set to patrol between point 1 to point 2 in room B, when the character player enters room B the zombie AI is then instructed to chase down and attack the player character.
Zombie B - will have the same commands as zombie A but will be tasked to patrol from point 2 to point 1.

So these rules I will be putting in place will be simple yet effective in my game, the algorithms will simulate the real word if zombies were to take over. It has the excitement factor, scariness and killing side of a game which fits the target audience of a lot of current day gamers.


Hack

The hack in this game will apply to the two zombies that there actions will be so predictable, the player character will know what the zombie plans to do before it has even happened. so to emphasise into a little more detail, the code applied to the zombie 1 will be the same applied to zombie 2, otherwise known as lazy code. This is not necessarily a hack but does make a difference in the end user experience, by just doing a little extra and applying a different objective to zombie 2 can make the difference in a game. Yet again hacks can also be useful, so in my game we have two zombies and you need to remember that zombies don't think, the only thing they know is how to chase down and eat the enemy (player character). So because of this if you apply a hack or same code (lazy code) to all of the zombies, if they are predictable and you know what the zombie AI plans to do before it happens then in this case good, zombies are predictable, we know what they are going to do before it happens so in this situation, a hack is a positive implement in this game.

In my first assignment I cover hacks in gaming AI (Introduction to: NWC603COM – Using AI in Computer Games Assignment 1 - 1.3 Hack). I cover where you can find hacks in a game, good and bad but I really need to cover the hacks involved in my game. So I will be apply very similar code to both of my zombie AI's, the only difference is when the zombies are patrolling between the two points in room B. Now as a end user (player) you expect the zombies to just come chasing after you, and they'll be rights, its a simple hack yet a positive hack because it emulates a zombie down to a tea because there predicable and brings a real world experience - well if zombies were to take over the world.

1.3 Tactics & Strategy's

Tactics & Strategy's

The element of using tactics and strategy's in gaming AI is one of importance and vision in the role of emerging the player into a game, what I mean by this is by using the element of tactics and stratigy's in game, it brings a game realism to life by imitating real life situations. I have talked about tactics and strategy's in a previous post in the my blog, (Introduction to: NWC603COM – Using AI in Computer Games Assignment 1 - 5.1 Tactics & Strategy's) in this post I talk about how tactics and strategy's are used in today's games and the role they have, in this post I will be looking at how tactics and strategy's will apply to my game idea.

"Because of this design choice, level designers effectively fill the role of the high-level AI in real-time strategy games. Level designers:

• Are responsible for placing enemies strategically.
• Must balance the difficulty settings for each level.
• Implement scripts to handle special situations." (3)

Now the initial idea of strategy in AI is setting the AI a plan of action for or in game, now Champandard makes the first point in that strategy for AI is used for placing the enemy AI in a strategic position, now my game only has two AI zombie but they will be placed in a position where they can one, reach each point and then as soon as the player character enters room B, they can attack without any obstacle in its path. Now my game is not in the greatest detail when it comes to setting and changing the difficulty of the AI, the example used by Champandard is that of a game that has levels meaning the higher level you go the harder the AI is to kill.When the environment changes to that which  requires special situations, this could be when a member of the AI team gets kill in action, for example the leader of the team could get taken out so in that case another member of the team would need to step up and become the leader of the group. Again in my game this type of strategy is not used because the their are only two AI zombies working together. 

"In games like Halo and Killzone, paths are computed with a custom heuristic. This means that combat factors are included when selecting the best path:

• Is the actor moving through the cone of fire of a teammate?
• Is the actor exposed to the player’s weapons?"(4)

Now I have kept with Champandard because he gives a great view on tactics in AI gaming, the element of tactics will be applied in my game because the goal of the Zombie AI is to attack and kill the player character, the two zombies will work together and bet set a tactic to surround the player character to each side which disables him from escaping the scene. The quote also does say that tactics link in with heuristics because the AI used the best path, a common trial and error process to gain the best result and decides which direction the AI will head next. You could say that based on the current tactic of the AI was to get to a location without being detected by the player character but in order to do this the AI would need to use heuristics to find out which path would be the best and would work, other pathfinding options would be to find the least expensive route but this might not be the right move as it could lead in the AI being detected.

Its important to factor into my game that the element of tactics and strategy's wont play a massive role in the final outcome of my game but having the zombies use a strategy to surround the player character instead of both using the same path which could allow the player character to escape the situation I feel makes the scene that little more wild for the user playing and adds difficulty to the game without apply a higher damage rate required to kill one of the zombies.