video game audio prototyping with half-life 2 :: granulation leonard j. paul videogameaudio.com

Video GameAudio

Prototypingwith

Half-Life 2::

Granulation

Leonard J. Paul

VideoGameAudio.com

VideoGameAudio.cominfo {at} VideoGameAudio.com

VCMM 2009Vancouver, BC

Slide 2 of 17

Overview

Overview of audio for video games

Why is audio prototyping important ?

Description of system

Demonstration

Q & A



Slide 3 of 17

Games Overview

Video games are a widespread form of “interactive entertainment”

Grand Theft Auto IV $500 million in sales in 24hrs vs. The Dark Knight's weekend opening of $158 million

Games are software with interactive content and require innovative technology to stay current



Slide 4 of 17

Game Audio Overview

Like film audio, game audio is comprised of speech, sound effects and music

However, unlike film audio, the audio is interactive and must respond to changes in gameplay

Older systems such as the Playstation 2 had little CPU power available to audio, so sample playback was all that was easily possible



Slide 5 of 17

Old-Gen Game Audio Workflow

Conventional methods before the current generation of game consoles (pre-2007) have required recompilation and game coder involvement to hear results which is typically slow:

Create

30 mins

Compile

5-30 mins

Run Game

3 mins

Locate

2-5 mins

Test

5 mins



Slide 6 of 17

Next-Gen Game Audio

Promises techniques such as wave-tracing reverbs, granulation and physical modeling

Game audio becomes a combination of older methods of sampled sound and newer generative sound design methods

Sound designer becomes familiar with procedural sound design techniques = scary ? ->



Slide 7 of 17

Next-Gen Game Audio Workflow

Devise a system that doesn't require recompilation of audio behaviours when changing procedural sound design

Test design interactively

Create

30 mins

Compile

5-30 mins

Run Game

3 mins

Locate

2-5 mins

Test

Interactive



Slide 8 of 17

Next-Gen Audio Prototyping

Allow sound designers to create their procedural sound designs in real-time while the game is running

Middleware solutions such as Wwise allow real-time tweaking of parameters, however only for existing patches and basic synthesis unless plugins are used

Use of Kismet within Unreal allows for some scripting



Slide 9 of 17

Game Audio Pipeline

GameCode

CommercialSoundTool

GameAudioTool

SoundDriverCode

GameAudioCode

OSC Layer

OSC Layer



Slide 10 of 17

Game Parameters to Granulation

Granulation is a good match for games as it requires many parameters which the game can provide (ex. RPM -> playback rate)

Physics allow for continuous control over playback of sample (ex. ragdoll -> foley)

Complexity overload

Lines of code ?



Slide 11 of 17

Open Sound Control (OSC)

OSC is open-source software that allows communication between the game and PD

OSC is included in PD extended and just requires the addition of several C++ modules into the game engine

Access to the game events while the game is running



Slide 12 of 17

Pure Data (PD)

Relatively easy to learn open-source interactive audio implementation environment

Can integrate directly into game code (as in EA's Spore), but not optimal as it is interpreted

Create compiled code from (simple) patches as shown by pd2j2me

public void met0Bang() { double a; a = counter.bang(); a = a * 3; a = a / 4; }



Slide 13 of 17

Audiomulch

Independent audio processing tool that is good for granulation

Doesn't support OSC but can receive MIDI control information from PD server

Easy to use and quick to prototype real-time adaptive musical ideas



Slide 14 of 17

Half-Life 2 Half-life 2 is a PC game/XBox that won over 40

“Game of the Year” awards in 2004 and allows users to change the maps and other content of the game using the “Source engine” technology in C++

Left 4 Dead and other games based on Source

Hammer editor allows for map editing

Make your own too



Slide 15 of 17

Half-Life 2 Source Mod

A mod is a modification of the game that can be quite simple or be advanced enough to create an entirely new game (ie. total conversion)

Change code using Microsoft's free compiler Visual C++ 2008 Express Edition

Cost for replicating this system is just the cost of the game - $19.95



Slide 16 of 17

HL2 Demonstration



Slide 17 of 17

Questions ?

Leonard J. Paul

email: info {at} VideoGameAudio.com

web: VideoGameAudio.com

video game audio prototyping with half-life 2 :: granulation leonard j. paul videogameaudio.com

Documents

gen game audio workflowdevise

game events

game engineaccess

physical modelinggame

comoverview overview

audio prototyping important

game coder involvement

sound effects