DETAILED CONTENTS

1 Introduction

1 The Genesis of Audio in Games

2 From Sample Playback to Procedural Audio

3 How to Use This Book

What This Book Is

What This Book Isn’t

2 The Role of Audio in Interactive and Immersive Environments

1 Inform, Entertain, Immerse

1 Inform: How, What

a Geometry/Environment: Spatial Awareness

b Distance

c Location

d User Feedback and Game Mechanics

2 Entertain

a Sound Design

b Music and the Mix

3 Defining Immersion

2 Challenges of Game Audio

1 Implementation

2 Repetition and Fatigue Avoidance

3 Interactive Elements and Prototyping

4 Physics

5 Environmental Sound Design and Modeling

6 Mixing

7 Asset Management and Organization

3 The Game Engine Paradigm

1 What Is a Game Engine

The Unity3D Project Structure

1 Level Basics 101

a 2D, 3D and Cartesian Coordinates

b World Geometry

c Lighting

d Character Controllers

e Cameras

2 Elements of a Level

a Everything Is an Object

b Transform

c Sprites

d Meshes

e Models

f Textures

g Shaders

h Materials

i Terrain

j Skyboxes

k Particles Systems

l Colliders

m Triggers/Trigger Zones

n Lighting

o Audio

p Prefabs

2 Sub Systems

1 Animation

2 Input

3 Physics

Rigidbodies and Collision Detection

Physics Materials

Triggers

Raycasting

4 Audio

5 Linear Animation

6 Additional Sub Systems

4 The Audio Engine and Spatial Audio

1 Listeners, Audio Clips and Audio Sources

1 The Audio Listener

Audio Clips

Audio Sources

2 Audio Source Parameters

3 Attenuation Shapes and Distance

a Spherical Spreading

b Sound Cones – Directional Audio Sources

c Square/Cube

d Volumetric Sound Sources

e 2D, 3D or 2.5D Audio?

4 Features of Unity’s Audio Engine

a Audio Filters

b Audio Effects

c Audio Mixers

2 Audio Localization and Distance Cues

1 Distance Cues

a Loudness

b Dry to Reflected Sound Ratio

c Low Pass Filtering With Distance

d Spatial Width

2 Localization Cues

a Localization on the Horizontal Plane

b Localization on the Vertical Plane

3 Implementing 3D Audio

a Object-based Audio and Binaural Renderings

b Working With HRTFs

c Multichannel Audio and Ambisonics

4 Optimizing Sound Design for Spatialization

a Putting It all Together

b Working With 2D and Multichannel Audio

c Working With Ambisonics

d Working With Object-Based Audio

5 Sound Design – The Art of Effectively Communicating With Sound

1 The Art of Sound Design

1 A Brief History of Sound Design

2 Sound Design – Basic Considerations

a Effective Sound Design

b Sound Design Guidelines

3 Getting the Right Tools

a Equalization

b Dynamic Range

c Reverberation

d Harmonic Processors

e Metering Tools

f Utilities

4 Microphones

a Microphone Choice: Dynamic vs. Condensers

b Mic Placement

5 Sound Design – Before You Start

a Always Use High Quality Material

b Don’t Get Too Attached

c Build and Learn

d Listen for the Expected and the Unexpected

e Layers

f Be Organized

g Communicate

h Experiment, Experiment, Experiment

2 Basic Techniques

1 Layering/Mixing

2 Pitch Shifting

a Playback Speed Modulation

b Granular Synthesis

c Fast Fourier Transform-Based Algorithms

3 Distortion

a Saturation

b Overdrive

c Distortion

d Bit Crushing

4 Compression

a Blending Through Bus Compression

b Transient Control

c Inflation

5 Equalization/Filtering

a Equalization for Sound Design

b Resonance Simulation

6 Harmonic Generators/Aural Exciters

7 Granular Synthesis and Granulation of Sampled Sounds

a Granular Synthesis Terminology

b Sound Design Applications of Granular Synthesis

8 DSP Classics

a Ring Modulation/Amplitude Modulation

b Comb Filtering/Resonators

9 Reverberation

a Indoors vs. Open Air

b Reverb Parameters

c Reverberation for Environmental Modeling

d Reverberation as a Dramatic Tool

10 Convolution

a Optimization

b Speaker and Electronic Circuit Emulation

c Filtering/Very Small Space Emulation

d Hybrid Tones

11 Time-Based Modulation FX

a Chorus

b Flanger

c Phasers

d Tremolo

12 Foley Recording

6 Practical Sound Design

1 Setting Up a Sound Design Session and Signal Flow

1 Signal Flow

a Input

b Inserts

c Pre-Fader Send

d Volume Fader

e Metering: Pre-Fader vs. Post Fader

f Post-Fader Send

g Output

2 Working With Video

a Know Your Frame Rate

3 Clipping Is Easy – Mind the Signal Path

Use the Dynamic Range

4 Setting Up a Basic Session for Linear Mixes and Cut Scenes

a Music, Dialog and Sound Effects

b Inserts vs. Effects Loops for Reverberation

c Setting Up the Mix Session

d Master Output and Sub Maste

e Submixes and Effects Loops

f Further Enhancements

2 Practical Sound Design and Prototyping

1 Guns

a One Shot vs. Loops

b General Considerations

c Designing a Gunshot

2 Prototyping Vehicles

a Specifications

b Selecting Your Material

c Processing and Preparing Your Material

d Building a Prototype

3 Creature Sounds

a Primary vs. Secondary Sounds

b Emotional Span

c Working With Vocal Recordings

d Working With Animal Samples

e Working With Non-Human or Animal Samples

4 An Adaptive Crowd Engine Prototype in MaxMSP

7 Coding for Game Audio

1 Why Learn to Code?

1 Syntax and Logic

2 Algorithms

3 Basic Object-Oriented Programming Concepts

a Procedural vs. Object-Oriented

b Encapsulation and Inheritance

2 An Intro to C#: Syntax and Basics

1 Our First Script

2 Variables, Constants, Data Types Operators, Arrays and Lists

a Data Types

b Variables

c Arrays

d Lists

e Access Modifiers

3 Accessing a Function From Another Class

3 Playing Audio in Unity

1 Our First Audio Script

2 Play() vs. PlayOneShot()

3 Using Triggers

4 Sample Randomization

5 Detecting Keyboard Events

6 Audio-Specific Issues

a Timing – Frame Rate vs. Absolute Time

b Linear vs. Logarithmic Amplitude

8 Implementing Audio: Common Scenarios

1 Before You Start: Preparing Your Assets

2 Ambiences and Loops

1 Creating Ambiences and Loops

a Seamless Loops

b Creating a Simple Loop – Looping Techniques

c Creating Variations

2 Implementing Our Loops in a Unity Level

a Challenges

b Spatial Distribution

c Working With the Time Property to Avoid Phasing Issues

3 Random Emitters

a A Simple Random Emitter Algorithm

b Coroutines

4 Ambiences, Putting It All Together

5 Sample Concatenation

a Creating Variations With Footsteps Samples

b Case 1: Swapping Audio Clips

c Case 2: Using PlayScheduled()

6 Collisions

a Detecting Collision

b Velocity-based Sample Selection

7 Raycasting and Smart Audio Sources

a Implementing Occlusion With Raycasting

b Avoiding the Pebble Effect

8 Animation Events

9 Audio Fades

10 Distance Crossfades

11 Working With Prefabs

a Creating a Smart Intermittent Emitter Prefab With Occlusion

b Instantiating a Prefab From Scripting

c Destroying an Object Instantiated From a Prefab

d Instantiating Audio Emitters at Random Locations in 3D

9 Environmental Modeling

1 What Is Environmental Modeling?

1 Reverberation

a Pre-Computed vs. Real Time Computation

b Absorption Coefficients

c Environmental Modeling With Reverberation in Unity

d Unity’s Reverberation Parameters

2 Best Practices for Environmental Modeling

a Late vs. Early Reflections

b Reflections Level

c Density and Diffusion

d High Frequencies vs. Low Frequencies

3 Reverb Zones, Effects Loops and Audio Reverb Filters

a Reverb Zones

b Adding Reverb as an Effect Loop Using the Mixer

c Audio Reverb Filters

2 Distance Modeling

1 Filtering as a Product of Distance

a Adding a Low Pass Filter That Will Modulate its Cutoff Frequency Based on Distance

b Width Perception as Product of Distance

c Dry to Wet Ratio as a Product of Distance

d Distance Simulation: Putting It All Together

3 Additional Factors

1 Occlusion, Obstruction, Exclusion

a Occlusion

b Obstruction

c Exclusion

2 Distance Crossfades

3 Doppler Effect

10 Procedural Audio: Beyond Samples

1 Introduction, Benefits and Drawbacks

1 What Is Procedural Audio?

a Procedural Audio, Pros and Cons

b Approaches to Procedural Audio

2 Practical Procedural Audio: A Wind Machine and a Sword Collision Model

1 A Wind Machine in MaxMSP With Subtractive Synthesis

Making the Model Flexible

2 A Sword Maker in MaxMSP With Linear Modal Synthesis

Spectral Analysis

Modeling the Impulse

Modeling the Resonances

Making the Model Flexible

11 Adaptive Mixing

1 What’s in a Mix? Inform and Entertain (Again)

1 Mix Considerations

2 Music, Dialogue and Sound Effects

3 Planning and Pre-Production

a SubMixing

b Routing

c Dynamic Range

d Passive vs. Active Mix Events

2 The Unity Audio Mixer

1 Adding Groups to the Unity Mixer

2 The Audio Group Inspector

3 Working With Views and Colors in the Unity Mixer

Creating Views in Unity

4 Adding Effects to Groups in Unity

5 Inserts vs. Effect Loops

6 Setting Up an Effect Loop for Reverberation in Unity Using Send and Receive

Note on Adjusting Levels During Gameplay

7 Ducking in Unity

Setting Up a Ducking Compressor in Unity

3 Snapshots, Automation and Game States

1 Working With Snapshots

2 Recalling Snapshots via Scripting

3 Editing Mixer and Plugin Parameters via Scripting

4 Exposing a Parameter: Controlling a Volume Slider

4 Good Practices

Mix Levels

12 Audio Data Reduction

1 Digital Audio: A Quick Review

1 Pulse Code Modulation

2 File Size Calculation

2 Data Reduction Strategies

1 Speech vs. Generic Audio

2 Bit Rates

3 Perceptual Coding

The Trade-Off

4 Common File Formats

a MP3

b Advanced Audio Coding

c Ogg Vorbis

d AC-3 Dolby Digital

e Adaptive Differential Pulse Code Modulation

3 Data Reduction Good Practices

4 Data Reduction Options in Unity

1 File Options

2 Load Type

3 Compression Formats Options

Sample Rate Setting

Index