What Exactly is a Game Engine?
A game engine is a software framework used by developers to build video games for consoles, mobile devices, PCs and other platforms more efficiently. Game engines provide the core functionality needed to design and develop games, handling tasks like:
- Rendering graphics
- Simulating physics
- Playing audio
- Detecting collisions
- Receiving input
- Powering artificial intelligence (AI)
- Facilitating networking capabilities for multiplayer games
In essence, game engines eliminate the need to code these common elements from scratch for each game. They allow developers to focus on higher-level tasks like gameplay logic, content creation, and user experience.
Modern game engines also include editors that provide a WYSIWYG (what you see is what you get) environment for building levels, placing objects, painting textures, animating characters and more. This makes game development faster compared to traditional hard-coding methods.
The Evolution of Game Engines
In the early days of the video game industry, games were written in assembly language or C, requiring developers to code their own engines for every title.
One of the first game engines that provided a reusable framework was Garry Kitchen‘s GameMaker in 1985. It allowed commodore 64 developers to create interactive games with built-in sprites, music, input handling and other features.
Over the 90s, consoles like the Sega Genesis and Super Nintendo had custom graphics chips that were challenging to program low-level code for. Game engines simplified development across platforms.
Id Software‘s Doom engine (released in 1993) and Quake engine (released in 1996) were breakthrough technologies, enabling 3D first-person shooter games with textures, lighting, and multiplayer support.
The Doom and Quake engines powered many iconic 90s first-person shooters like Half-Life, Unreal Tournament, Medal of Honor, and more.
In the early 2000s, game engines like RenderWare provided a solution for quickly porting games to multiple platforms. Epic Games also released the first version of Unreal Engine in 1998, aiming to power AAA-quality games.
Today, Unreal Engine and Unity are considered industry-leading game engines that dominate the market. Modern engines give developers an integrated development environment (IDE) to build high-end 2D and 3D games for consoles, PC, mobile and even films/TV.
Key Capabilities of Game Engines
While early game engines focused mainly on graphics, today‘s engines offer a vast array of capabilities:
Rendering and Graphics
State-of-the-art game engines leverage GPU acceleration to render incredibly detailed 2D and 3D worlds. Their advanced rendering capabilities enable effects like shadows, lightmaps, motion blur, particles, realistic water simulation and more.
For example, Unreal Engine‘s Nanite technology virtualizes geometry to allow film-quality assets with millions of polygons to be rendered in real-time. Unity‘s High Definition Render Pipeline (HDRP) also produces cinema-grade visuals.
Artificial Intelligence
Sophisticated AI systems allow game engines to power everything from pathfinding algorithms that guide NPC movements to complex squad behaviors and decision-making during combat situations.
Smart use of AI can enable more dynamic, emergent gameplay with characters that respond realistically to players‘ actions. AI capabilities in modern engines keep improving thanks to machine learning integration.
Animation Systems
Specialized animation toolsets allow developers to breathe life into game characters and objects. Keyframe animation, blend trees, inverse kinematics, mesh skinning and other techniques enable believable movements and interactions.
Physics Simulation
Game engines come with built-in physics systems for implementing gravity, mass, friction, collision detection and rigid body dynamics, essential for realistic gameplay. Nvidia‘s PhysX and Havok are popular physics engines integrated into platforms like Unreal.
Audio Systems
Robust audio tools allow developers to incorporate immersive 3D spatial sound effects, character voices, dynamic music and other sonic elements that heighten engagement during gameplay.
Networking Capabilities
Game engines ease the process of getting multiplayer games up and running across platforms. They handle low-level network communication protocols enabling complex online experiences with features like lobbies, matchmaking, chat systems, player persistence and lag compensation.
Cross-Platform Publishing
A huge advantage of modern game engines is their ability to develop a game once and deploy it across consoles, PC, mobile and more. Some engines also enable creating games for VR/AR headsets. Streamlined porting saves enormous effort compared to platform-exclusive game development.
Live Ops & Monetization Tools
Many engines now provide live ops capabilities for running games as a service, along with tools for managing in-game economies. These features help developers refine gameplay balance, create compelling progression/reward systems and monetize effectively post-launch.
Popular Game Engines Compared
While lots of game engines exist, let‘s compare some of the most prominent options:
Unreal Engine
- Created by: Epic Games
- Release date: 1998
- Supported platforms: PC, consoles, mobile, VR/AR
- Notable games powered by Unreal Engine: Fortnite, Gears of War series, Batman: Arkham series, BioShock series
- Pricing model: free to use with 5% royalty on gross product revenue after $1 million
- Key features: next-gen rendering capabilities, extensive content library, Blueprint visual scripting, C++ programming, sequencer cinematics toolset, MetaHumans creator, Quixel megascans library
Unity
- Created by: Unity Technologies
- Release date: 2005
- Supported platforms: PC, consoles, mobile, VR/AR
- Notable games powered by Unity: Pokemon Go, Beat Saber, Ori and the Blind Forest, Hollow Knight
- Pricing model: free limited version, paid Plus/Pro subscriptions start from $399/year per seat
- Key features: performant 2D/3D rendering, C# programming, visual shader editor, animator state machine, bake lighting into lightmaps, run natively on mobile devices, create digital human characters using MARS
Unreal Engine vs Unity: Key Differences
While both engines are capable of powering advanced games, some notable differences exist:
- Unreal uses C++ while Unity relies on C# programming
- Unreal offers photorealistic graphics quality out of the box while Unity graphics require more custom shaders/pipelines
- Unity has traditionally been more 2D/mobile friendly while Unreal caters well to AAA games
- Unity has a reputation for being simpler to learn than Unreal
- Unreal marketplace offers more premium quality content than Unity asset store
Ultimately both platforms have powered breakout indie hits as well as big-budget AAA blockbusters. The engine chosen depends primarily on the game vision, team skills and resources.
Other Game Engines
Besides Unreal and Unity, other common game engines include:
- CryEngine: Used for photorealistic first-person shooters like Far Cry series
- Frostbite Engine: Powers EA games like Battlefield, FIFA, Need for Speed series
- Amazon Lumberyard: Free AAA engine deeply integrated with AWS cloud services
- Godot: Open source 2D/3D engine focused on having an approachable workflow
- GameMaker Studio 2: Beginner-friendly engine useful for 2D games
Why Game Engines Are Essential
While games engines aren‘t mandatory for game development, they provide compelling advantages:
Faster Iteration: Game engines significantly speed up building and testing gameplay compared to coding everything from scratch. Developers gain quick feedback to calibrate mechanics.
Cross-platform Publishing: Modern engines allow you to develop once yet deploy across a range of platforms like PC, consoles, mobile etc.
Rich Features Set: Engines offer an abundant collection of modules to tap into for graphics, physics, AI, audio, animations, effects and more.
Collaborative Workflow: They enable easier collaboration between programmers, designers and artists with tools tailored to each discipline.
Industry-Standards: Learning to use dominant industry-standard tools like Unreal and Unity makes you more employable.
Asset Stores: Marketplaces like Unreal Engine marketplace and Unity Asset store offer pre-made 3D models, environments, visual effects and more to use in your games.
While an experienced programmer could theoretically build their own custom engine, leveraging existing game engines saves tremendous effort and enables focusing on your game‘s unique value.
Game Engines Powering Major Game Franchises
To appreciate the capabilities of modern game engines, let‘s look at some hit franchises built using them:
Final Fantasy VII Remake
This remake of the iconic JRPG masterpiece was built using Unreal Engine 4. The engine delivers jaw-dropping graphics with meticulously detailed characters and environments, bringing Midgar to life like never before.
Microsoft Flight Simulator
Microsoft Flight Simulator harnesses Azure cloud computing along with satellite data to render the entire planet in rich detail that you can seamlessly fly around. Powered by a proprietary engine, it sets a new bar for realism.
Genshin Impact
This free-to-play action RPG has enraptured over 50 million players on PC and mobile. Built using Unity engine, it provides an anime-style open-world packed with quests, puzzles and fast-paced combat.
As these examples demonstrate, modern game engines offer almost limitless potential for game creators to bring incredible worlds to life.
Custom Game Engines
While Unreal and Unity dominate the landscape, some developers build proprietary game engines customized for their specific needs.
For instance, Epic‘s Chaos engine will power physics simulation in the upcoming high-budget game Fortnite 2 leveraging their internal R&D.
Rockstar Games has the powerful RAGE engine tailored to deliver unprecedented immersion in vast open worlds starting from Grand Theft Auto IV.
Bethesda Game Studios‘ Creation engine (now upgraded to Creation Engine 2) powers The Elder Scrolls series and Fallout franchise enabling complex gameplay systems in sandbox worlds.
Though expensive to develop and maintain, custom engines finely tuned to a studio‘s requirements can maximize innovation.
The Future of Game Engines
As gaming hardware grows exponentially stronger in terms of CPU, GPU and memory capacity, game engines will scale up to leverage these resources for richer virtual worlds.
Photorealism across environments, characters and effects is an endless pursuit. Ray tracing acceleration in hardware and neural graphics networks indicate graphics will achieve cinema-grade fidelity.
More intelligent AI promising emergent gameplay along with virtualized NPCs who behave realistically are areas of active R&D.
As AR/VR/MR headsets mature both technically and in adoption, game engines will further tune their capabilities towards immersive extended reality experiences spanning the physical and digital realm.
The ease of creating vast, dynamic environments filled with high-quality personalized content without needing massive art teams is also a direction innovators are focusing on via procedural content generation methods and machine learning.
Cloud gaming infrastructure and 5G networks aim to enable streaming visually stunning AAA games seamlessly across devices by having remote servers run games too intensive for local hardware. Multiplayer serverload balancing also poses unique scaling challenges.
While the core purpose remains bringing creative visions to gamers through interactivity, game engines must constantly evolve across vectors like graphics, physics, AI, animation, audio and infrastructure to turn imaginative worlds into reality using code as the lifeblood.
Summary
Game engines are foundational platforms that provide reusable modules developers integrate to build video games faster and with rich capabilities. They handle rendering graphics, playing audio, simulating physics, implementing AI behaviors and more so programmers can work on higher-level game logic and content creation.
We traced the evolution of game engines from early software like GameMaker to modern feature-packed engines like Unreal and Unity that dominate the gaming landscape. Key engine capabilities spanning graphics, animation, audio, AI, VR/AR support, networking etc. were discussed along with custom in-house engines made by some studios.
Robust game engines offer numerous advantages in accelerating prototyping ideas, collaborating efficiently within specialized teams, achieving cross-platform support and ultimately creating captivating gameplay experiences pushing the envelope of possibility. As gaming technology progresses rapidly, game engines must keep pace to build the awe-inspiring worlds that next-gen gamers eagerly await.
