Friday, April 06, 2007

Moving Parts

This is where I intend to catalog (all?) the components of a commercial game. I will periodically update this post.


I've bought and read many books on game development. The bad ones are generally 1000 pages of C++ source code. The good, useful ones tend to fall into two categories.

  • Narrow and deep (books that equate 'game engines' and 'rendering engines', for example)
  • Broad and shallow (books that contain light sections on rendering, sound, networking, data structures, etc.)
Still, even books in the broad category aren't that broad. The reason? Books can only be so thick. My point really is that the practice of game development includes a vast array of subspecialties and I'd kinda like to enumerate them here. Hopefully with input from my readers (that's you, Mom) that I'll add. So this list will be ultra-broad with no depth whatsoever. Depth will have to wait for subsequent posts.

Now, not every game will have or need all these systems, but it's crazy just how many most games will need. So, for right now, this is a brain dump and I've only just begun..


Content Creation - tools - geometry, mesh creation
Content Creation - tools - geometry, mesh creation - offline CSG tools
Content Creation - tools - image creation
Content Creation - tools - motion capture cleaning
Content Creation - tools - higher level 'world' assembly, including assigning gameplay attributes to objects
Content Creation - tools - sound creation/mixing/production
Content Creation - tools - mission/level creation
Content Creation - tools - statistical data, skill/inventory data and attributes
Content Creation - tools - state machine creation
Content Creation - tools - script debuggers, interactive interpreters for testing
Data Management - managing generated code
Data Management - asset dependency management
Data Management - geometry processing - ie. adding attributes, triangle stripification
Data Management - texture processing - texture packing, format conversions, bit depth conversion, etc.
Data Management - asset databases (SQL, XML)
Data Management - metadata collection about assets, data mining for global performance enhancement, data mining for content creation automation, etc.
Data Management - version control systems
Code Management - Code Generation - from asset databases, other offline sources
Code Management - Build System - standard way of building the game for all developers
Code Management - Library/Component Management - system(s) for cataloging, versioning and incorporating libraries and reusable components
Code Management - version control systems
Testing Systems and Methodologies

(much more offline/pipeline side to come; the game pipeline gets far less attention than it deserves, often with disastrous results)


System - threading libraries/primitives
System - error handling, logging, assert handling
System - string handling, regular expressions
System - elementary data structures, STL, etc.
System - fast math primitives
I/O - File - standard file i/o
I/O - File - file compression/decompression
I/O - File - loading game assets (meshes, textures, scripts, game data files, etc..)

I/O - File - low-level game asset caching
I/O - File - asset 'packaging' into larger files
I/O - File - object serialization support
I/O - Network - lobby
I/O - Network - server side
I/O - Network - event handling (see Events below)
I/O - Network - publishing player data to online services
I/O - Network - web access services
Localization Support - text databases
Memory - efficient game asset caching
Memory - memory pooling systems
Memory - garbage collection systems
Events - event handling/dispatching systems
Events - 'replayable' game state management
Events - game state represented as loadable/saveable data stream
Events - game state policies - random/deterministic, etc..

Events - game 'flow' management
Sound - Mp3, WAV, Ogg, etc. playback
Sound - runtime mixing, filters

Sound - in game capture
Sound - stereo, 5.1 surround sound
Sound - 3d audio
Input - console controller
Input - force feedback (output)
Input - spatial (Wii, SIXAXIS)
Input - mouse
Input - keyboard
Input - other (Guitar Hero, EyeToy, DDR, Donkey Konga)
Graphics - rendering - geometry processing
Graphics - rendering - geometry processing - progressive meshes and LODs
Graphics - rendering - geometry processing - efficient spatial subdivision
Graphics - rendering - shader(s), per pixel lighting

Graphics - rendering - scene graph management
Graphics - rendering - GPU based utilities for non-graphics
Graphics - rendering - geometry processing - in game CSG operations
Graphics - geometry processing - human animation

Graphics - geometry processing - motion capture
Graphics - rendering - decaling
Graphics - rendering - particle systems
Graphics - rendering - dynamic skyboxes/skydomes
Graphics - images - loading/encoding image formats - DDS, TGA, JPG, etc.
Physics - collision detection
Physics - collision detection - geometry processing
Physics - collision handling, mesh processing for non-rigid object effects
Physics - ragdoll animation
Physics - wind, environmental effects
Gameplay/AI - script
Gameplay/AI - state machine systems
Gameplay/AI - classical AI algorithms
Gameplay/AI - events - collisions, sphere of influence effects, NPC line of sight, NPC earshot

Gameplay - Cars - Damage Models
Gameplay - Cars - Driving Models
Geometry - Modeling

Geometry - Inverse Kinematics
Geometry - Rigging/Tagging/Markup
Geometry - Animation
Geometry - Procedural Animation (ie. Cloth, Hair, Jelly/Spring Models, etc..)
Geometry - Facial Performance and Lip Sync'ing
Rendering - Textures
Rendering - Shaders
Rendering - Animated textures/maps
Video - codec(s)/playback - MPEG, MJPEG, WMV, VP6, Bink, Madcow, etc..
Video - color space conversion
UI - rendering
UI - event handling systems, architecture and data
UI - script
UI - some games have a large amount of UI (ie. Madden, with its enormous UI)

Data Management - embedded SQL database (not just for plain-old IT anymore)
Embedded Control - script languages
Control - in-game gameplay tweaking utilities, runtime assets updating support


Online Game Services

Online - lobby
Online - server side
Online - (deterministic) player position prediction and tracking (online multiplayer)
Online - publishing player data to online services
Online - web access services
Online - billing tracking for online services (online multiplayer)

Online - player data storage
Online - accessibility from PC website

(more to come, but I'm sleepy now and I want to go to bed..)


Joe said...

You're missing all the non-graphical stuff on the content creation side: sounds, missions, inventory item type data, skill data. Those all have content creation tools, and many have data mangement tools.

The runtime code to handle player motion synchronization doesn't see to fit the existing categories.

There's a whole other top level group for tools that monitor the game at runtime... I'm thinking operations tools to manage servers and monitor the data in those SQL databases. There could also be quite a bit of tooling for in-game customer support, out of game customer support, billing integration and the like.

Publishing player data to services like Xbox live or WoW's Armory deserves some mention too. I guess that would be web access systems.

Senzee said...

Awesome, yeah - that's the kind of stuff I'm looking for.