Tech Guides - Game AI

"A computer would deserve to be called intelligent if it could deceive a human into believing that it was human" — Alan Turing It is quite common to find games which are initially exciting but take a boring turn eventually, making you want to quit the game. Then, there are games which are too difficult to hold your interest and you end up quitting in the beginning phase itself.  These are also two of the most common problems that game developers face when building games. This is where AI comes to your rescue, to spice things up. Why use Artificial Intelligence in games? The major reason for using AI in games is to provide a challenging opponent to make the game more fun to play. But, AI in the gaming industry is not a recent news. The gaming world has been leveraging the wonders of AI for a long time now. One of the first examples of AI is the computerized game, Nim, was created back in 1951. Other games such as Façade, Black & White, The Sims, Versu, and F.E.A.R. are all great AI games, that hit the market long time back. Even modern-day games like Need for Speed, Civilization, or Counter-Strike use AI. AI controls a lot of elements in games and is usually behind characters such as enemy creeps, neutral merchants, or even animals. AI in games is used to enable the non-human characters (NPCs) with responsive, adaptive, and intelligent behaviors similar to human-like intelligence. AI helps make NPCs seem intelligent as they are able to actively change their level of skills based on the person playing the game. This makes the game seem more personalized to the gamer. Playing video games is fun, and developing these games is equally fun. There are different game engines on the market to help with the development of games. A game engine is a software that provides game creators with the necessary set of features to build games quickly and efficiently. Let’s have a look at the top game engines for Artificial Intelligence game development. Unity3D Developer:  Unity Technologies Release Date: June 8, 2005 Unity is a cross-platform game engine which provides users with the ability to create games in both 2D and 3D. It is extremely popular and loved by game designers from large and small studios alike. Apart from 3D, and 2D games, it also helps with simulations for desktops, laptops, home consoles, smart TVs, and mobile devices. Key AI features: Unity offers a machine learning agents toolkit to the game developers, which help them include AI agents within games. As per the Unity team, “machine Learning Agents Toolkit (ML-Agents) is an open-source Unity plugin that enables games and simulations to serve as environments for training intelligent agents”. Unity AI - Unity 3D Artificial Intelligence  The ML-Agents SDK transforms games and simulations created using the Unity Editor into environments for training intelligent agents. These ML agents are trained using deep Reinforcement Learning, imitation learning, neuroevolution, or other machine learning methods via Python APIs. There’s also a TensorFlow based algorithm provided by Unity to allow game developers to easily train intelligent agents for 2D, 3D, and VR/AR games. These trained agents are then used for controlling the NPC behavior within games. The ML-Agents toolkit is beneficial for both game developers and AI researchers. Apart from this, Unity3D is easy to use and learn, compatible with every game platform and provides great community support. Learning Resources: Unity AI Programming Essentials Unity 2017 Game AI programming - Third Edition Unity 5.x Game AI Programming Cookbook Unreal Engine 4 Developer: Epic games Release Date: May 1998 Unreal Engine is widely used among developers all around the world. It is a collection of integrated tools for game developers which helps them build games, simulations, and visualization. It is also among the top game engines which are used to develop high-end AAA titles. Gears of War, Batman: Arkham Asylum and Mass Effect are some of the popular games developed using Unreal Engine. Key AI features: Unreal Engine uses a set of tools which helps add AI capabilities to a game. It uses tools such as behavior Tree, navigation Component, blackboard asset, enumeration, target point, AI Controller, and Navigation Volumes. Behavior tree creates different states and the logic behind AI. Navigation Component helps with handling movement for AI. Blackboard Asset stores information and acts as the local variable for AI. Enumeration creates states. It also allows alternating between these states. Target Point creates a basic Path node form. The AI Controller and Character tool is responsible for handling the communication between the world and the controlled pawn for AI. At last, the Navigation Volumes feature creates Navigation Mesh in the environment to allow easy Pathfinding for AI. There are also features such as Blueprint Visual Scripting which can be converted into performant C++ code, AIComponents, and the Environment Query System (EQS) which provides agents the ability to perceive their environment. Apart from its AI capabilities, the Unreal engine offers the largest community support with lifetime hours of video tutorials and assets. It is also compatible with a variety of operating platforms such as iOS, Android, Linux, Mac, Windows, and most game consoles. But there are certain inbuilt-tools in Unreal Engine which can be hard for beginners to learn. Learning resources: Unreal Engine 4 AI programming essentials CryEngine 3 Developer: Crytek Release Date: May 2, 2002 CryEngine is a powerful game development platform that comes packed with a set of tools and features to create world-class gaming experiences. It is the game engine behind games such as Sniper: Ghost Warrior 2, SNOW, etc. Key AI features: CryEngine comes with an AI system designed for easy creation of custom AI actors. This is flexible enough to handle a larger set of complex and different worlds. The core of CryEngine’s AI system is based on lots of scripting. There are different AI elements within this system that add the AI capabilities to the NPCs within the game. Some of these elements are AI Actions which allows the developers to script AI behaviors without creating new code. AI Actors Logger can log AI events and signals to files. AI Control Objects use AI object to control AI entities/actors. AI Debug Draw is the primary tool offered by CryEngine for information on the current state of the AI System and AI actors. AI Debugger registers the inputs that AI agents receive and the decisions that they make in real-time during a game session. AI Sequence system works in parallel to FG and AI systems. This helps to simplify and group AI control. CryEngine offers the easiest A.l. coding of any tech currently on the market. Since CryEngine is relatively new as compared to other game engines, it does not have a very flourishing community yet. Despite the easy AI coding, the overall learning curve of Unreal Engine is high. Panda3D Developer: Disney Interactive until 2010,  Walt Disney Imagineering, Carnegie Mellon University Release Date: 2002 Panda3D is a game engine, a framework for 3D rendering and game development for Python and C++ programs. It includes graphics, audio, I/O, collision detection, and other abilities for the creation of 3D games. Key AI features: Panda3D comes packed with an AI library named PandAI v1.0. PandAI is an AI library which provides 'Artificially Intelligent' behavior in NPC (Non-Playable Characters) in games. The PandAI library offers functionality for Steering Behaviors (Seek, Flee, Pursue, Evade, Wander, Flock, Obstacle Avoidance, Path Following) and path finding (helps the NPCs to intelligently avoiding obstacles via the shortest path ). This AI library is composed of several different entities. For instance, there’s a main AIWorld Class to update any AICharacters added to it. Each AICharacter has its own AIBehavior object for tracking all the position and rotation updates. Each AIBehavior object has the functionality to implement all the steering behaviors and pathfinding behaviors. These features within Panda3D gives you the ability to call the respective functions. Panda3D is a relatively simple game engine which lets you add AI capabilities within your games. The community is not as robust and has a low learning curve. AI is a fantastic tool which makes the entities in games seem more organic, alive, and real. The main goal here is not to copy the entire human thought process but to just sell the illusion of life. These game engines provide the developers with the entire framework needed to add AI capabilities to their games. The entire game development process is more fun as there is no need to create all systems including the physics, graphics, and AI, from scratch. Now, if you’re wondering about the best AI game engines out of the four mentioned in this article then there is no specific answer to that as selecting the best AI game engine depends on the requirements of your project. Game Engine Wars: Unity vs Unreal Engine Unity switches to WebAssembly as the output format for the Unity WebGL build target Developing Games Using AI