3D Game
Programming
王銓彰
kevin.cwang@msa.hinet.net
2005
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課程大綱
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Introduction to Game Development (3hr)
Game System Analysis (3hr)
The Game Main Loop (3hr)
3D Game Engine Training (Using TheFly3D) (6hr)
Game Mathematics & Geometry (3hr)
Terrain (3hr)
Characters (3hr)
Game Control System (3hr)
Advanced Scene Management System (3hr)
Game AI (6hr)
Game Physics (3hr)
Game FX (3hr)
Network Gaming (3hr)
MMOG (3hr)
Summary
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Wang’s Method for Real-time 3D Game Development
2
課程要求
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One term project
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The students are in teams.
Use TheFly3D 3D engine to code a Real-time 3D Game.
 Action RPG
The teacher will provide graphics materials and setup the game
design.
Final examination
Homework will be closely coupled with the term project.
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王銓彰 (1/3)
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目前
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學歷
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數位內容學院 專任講師 / 顧問
宇峻奧汀 顧問
鈊象電子 3D技術顧問
台灣大學土木工程學系畢業
資歷
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04-04 資策會網路多媒體研究所 專案顧問
97-04 昱泉國際股份有限公司 技術長
96-96 虛擬實境電腦動畫股份有限公司 研發經理
93-96 西基電腦動畫股份有限公司 研發經理
90-93 國家高速電腦中心 助理研究員
89-90 台灣大學土木工程學系 CAE Lab 研究助理
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王銓彰 (2/3)
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Game作品
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Current
 TheFly3D 3D Engine
昱泉國際
 DragonFly 3D Game Engine
 M2神甲奇兵, VRLobby, 天劍記
 Lizard 3D Game Engine
 幻影特攻、笑傲江湖 I & II、神鵰俠侶 I & II、風雲、小李飛刀、
笑傲江湖網路版、怪獸總動員、聖劍大陸、笑傲外傳
西基電腦動畫
 Ultimate Fighter
 1st real-time 3D fighting game in Taiwan
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王銓彰 (3/3)
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專長 (Expertise)
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3D Computer Graphics
Geometric Modeling
Numerical Methods
Character Animation
Photo-realistic Rendering
Real-time Shading
Volume Rendering
應用領域 (Applications)
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即時3D遊戲開發 (Real-time 3D Game Development)
電腦動畫 (Computer Animation)
虛擬實境 (Virtual Reality)
電腦輔助設計 (Computer-aided Design, CAD)
科學視算 (Scientific Visualization)
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1st
Introduction to
Game Development
7
Introduction to Game Development
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Game
Game
Game
Game
Game
Tools
platform
types
team
development pipeline
software system
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Game Platform
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PC
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Console
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Single player
Match Makings
MMOG (Massive Multi-player Online Game)
Web-based Games
Sony PS2
MS Xbox
Nintendo GameCube
Arcade
Mobile
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Nintendo GBA
Nintendo DS
Sony PSP
Hand-held
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Game Development on PC
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PC is designed for general office application.
Not for entertainment purpose
A virtual memory system
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But video memory is limited.
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For frame buffers, z buffers, textures, vertices, …
PCI / AGP might be a problem for performance.
Open architecture
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Unlimited system memory
Hardware driver version issue
Different capabilities
Different performance
Compatibility test is very important.
Development is easy to setup.
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Visual C/C++ with DirectX
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Game Development for Consoles
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Specific hardware designed for games
Single user OS
Single process OS
No hard disk drive (?)
Closed system
Native coding environment
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Limited resources
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Proprietary SDK
Hardware related features
C language with assembly
Memory for everything
 32M for PS2
 64M for Xbox
One console runs, the others do !
Use gamepad and no keyboard
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Game Types
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RPG (Role playing games)
AVG (Adventure games)
RTS (Real-time strategy games)
FPS (First-person shooting games)
RSLG (戰棋)
STG
Sports
Action
Puzzle games
Table games
MMORPG
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Massive Multiple Player Online Role Playing Games
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Game Team Members
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開發團隊
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行銷業務團隊
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產品經理(PM)
測試團隊
遊戲審議委員會
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製作人
執行製作人
企劃團隊
程式團隊
美術團隊
Game project approval
遊戲經營團隊
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線上遊戲 game master (GM)
Customer services
MIS
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Game Producer 遊戲製作人
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Team leader (usually)
資源管理 (Resource management)
行政管理 (Administration)
專案管理 (Project management)
向上負責 (Upward management)
團隊的決策
風險管理
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遊戲執行製作人
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專案管理執行
Daily 運作
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House keeping
Meeting coordinator
Schedule checking
Cross-domain communication
Usually not a full-time job position
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A position for training and becoming a producer
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遊戲企劃 (1/2)
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故事設計 (Story telling)
腳本設計 (Scripting)
玩法設計 (Game play design)
角色設計(Character design)
動作設計(Animation design)
關卡設計 (Level design)
特效設計(Effect design)
物件設計
介面設計(User Interface design)
遊戲調適 (Game tuning)
數值設定 (Numerical setup)
AI 設計 (Game AI design)
音效設定 (Sound FX setup)
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遊戲企劃 (2/2)
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場景設定 (Scene setup)
Game document writing
Game quality checking
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遊戲美術
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Visual setup for game design
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2D setup
3D setup
Graphics design and production
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場景 (Terrain)
人物 (Character)
建模 (Models)
材質 (Textures)
動作 (Motion / Animation)
特效 (FX)
User Interface
行銷支援 (封面.海報..等)
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遊戲程式
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遊戲程式 (Game Program) 撰寫
遊戲開發工具 (Game Tools) 開發
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遊戲Data exporters from 3D animation Software
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Level editor
Scene editor
FX editor
Script editor
Game editor
3dsMax / Maya / Softimage
Game engine development
Game technique research
Online game server development
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遊戲開發流程
Basic Procedures for Game Development
Idea
Proposal
Concept
Approval
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Production
Prototype
發想 (Idea)
提案 (Proposal)
製作 (Production)
整合 (Integration)
測試 (Testing)
 除錯 (Debug)
 調適 (Tuning)
Integration
Pre-alpha
Testing
Debug
Alpha
Tuning
Beta
Final
> Concept approval
> 雛形 (prototype)
> Pre-alpha
> Alpha
> Beta
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遊戲發想(Concept Design)
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遊戲類型 (Game types)
遊戲世界觀 (Game world)
故事 (Story)
遊戲特色 (Features)
遊戲玩法 (Game play)
遊戲定位 (Game product positioning)
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競爭對手評估
風險評估 (Risk)
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Target player
Marketing segmentation / positioning
SWOT (Strength/Weakness/Opportunity/Threat) 分析
產出物
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Concept Design Document (CDD)
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遊戲提案(Proposal)
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系統分析 (System analysis)
GDD 撰寫 (Game design document)
MDD 撰寫 (Media design document)
TDD 撰寫 (Technical design document)
遊戲專案建立 (Game project)
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Schedule
Milestones / Check points
Risk management
測試計畫書
團隊建立 (Team building)
產出物
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GDD
MDD
TDD
The Team
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遊戲開發(Production)
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美術量產製作
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Modeling
Textures
Animation
Motion
FX
量產 !
程式開發 (Coding)
企劃數值設定
…
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遊戲整合(Integration)
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關卡串聯 (Level integration)
數值調整 (Number tuning)
音效置入 (Audio)
完成所有美術
程式與美術結合
Testing within the game team
Focus group (User study)
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Release some playable levels for focus group.
Get the feedback from focus group to adjust the game play.
Invited outside game players but evaluation in-house
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遊戲測試(Test)
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Alpha 測試
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Beta 測試
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除錯 (Debug)
Make the game stable
數值微調
Game play 微調
對線上遊戲而言 (MMOG)
 封閉測試 (Closed beta)
 Invited game players
 開放測試 (Open beta)
 Free for public players
極限測試 (Critical testing)
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Only for MMOG
Continuously implementing
For servers
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Bugs
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Bug 分級 (Bug Classification)
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A Bug
B Bug
C Bug
S Bug
Bug
Bug Classification
Principles
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Bug 分級從嚴
Tester vs Debugger
Bug Dispatch
Debug
N
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Verify
Y
FAQ
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Game Software System
Game
NPC System
Virtual Agent
Fighting System
Terrain
Trading System
FX System
Game AI
Collision Character Dynamics
3D Scene Mngmt
3D Graphics API
2D Sprite
Gamepad
2D API
Hardware
Story
Script System
Sound FX
Audio
Input Device
UI
Network
OS API
Game Play
Layer
Engine
Layer
System
Layer
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System Layer – APIs (1/2)
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3D Graphics API
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2D API
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DirectX 9.0 SDK - DirectMedia
Win32 GDI
Input device
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DirectX 9.0 SDK – Direct3D
 Newest update : DirectX 9.0c SDK Update (June, 2005)
OpenGL
 2.0
DirectX 9.0 SDK – DirectInput
Audio
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DirectX 9.0 SDK – DirectSound / Direct3DSound / DirectMedia
OpenAL
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System Layer – APIs (2/2)
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OS API
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Win32 SDK
MFC
Network
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DirectX 9.0 SDK – DirectPlay
Socket library
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Engine Layer (1/2)
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3D scene management system
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Scene graph
Shaders
2D sprite system
Audio system
Gamepad
Hotkeys
Mouse
Timers
Network
DDK interface
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Engine Layer (2/2)
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Terrain system
Advanced scene management system
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Character system
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Bone-skin
Motion Blending
Dynamics
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Space partition technique
 BSP Tree
Octree
Particle system
Rigid-body dynamics
Collision detection
Sound FX
User interface
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Game Play Layer
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NPC (Non-playable characters) management
Game AI
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Path finding
Finite state machine (FSM)
Steering behavior
Avatar
Combat system
FX system
Script system
Trading system
Number system
…
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Game Development Tools for Programming (1/2)
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System Tools
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Visual C/C++
 .Net 2003
 VC/C++ 7.1
 Visual C/C++ 6.0 + SP5
NuMega BoundsChecker
 Finding memory leaking
Intel vTune
 Finding computation performance bottlenecks
 for CPU
PIX
 Finding graphics performance bottlenecks
 For GPU
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Game Development Tools for Programming (2/2)
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SDKs
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System API
 Win32 SDK or MFC
 DirectX SDK or OpenGL
 Socket library
Middleware (Game engine)
 Renderware
 Unreal
 …
Physics
 ODE
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Game Development Tools for Artists
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3D tools
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2D tools
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Discrete 3dsMax
Maya
Softimage XSI
Photoshop
Illustrator
Motion tools
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Motion capture devices
Motion Builder
FiLMBOX
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2nd
Game System Analysis
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What Will We Talk
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The idea about system analysis (SA)
Mind mapping
Case study - Term project
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Why System Analysis (1/2)
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For 程式結構 analysis
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To identify 工作量
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New game engine ?
Re-used code ?
Tools needed to be developed ?
For 資源 management
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The main program
Game development tools
Total man month
How many programmers ?
How good the programmers ?
For job dependency analysis
Job A
Job B
Job D
Job C
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Why System Analysis (2/2)
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To do technical possibility analysis
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Pre-processor for
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技術可行性分析
R&D ?
Where is the technical bottleneck ?
Technical design document
Project management
Bridge from game design to programming
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Something about System Analysis
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No standard procedures or approaches
It’s not a theory.
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Experience
You can use your own method/tool
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UML
Mind mapping
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心智圖法
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This is the one we will use in this course
…
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Wang’s System Analysis Steps
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Brainstorming
Integration
Dependency analysis
Create the project
Technical design document (TDD) writing
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Brainstorming
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Based on the game design to put everything as many as
you could
Use mind mapping
Including
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Game system
 Combat / Village / Puzzle / …
Program modulus
 Camera / PC control / NPC AI / UI / FX /…
Tools
 Level editor / Scene editor / …
Entities in games
 Characters / vehicle / terrain / audio / …
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Integration
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Confirm the resource limitation
Technical implement possibility
Put all related items together
Man month analysis
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How many ?
Who ?
Jobs / System identification
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Dependency Analysis
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Sort the Jobs
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By job dependency
By programmers’ schedule
Prototype for scheduling
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System Analysis – Create the Project
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Scheduling
Job assignment
Resource allocation
Check points
Milestones
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Major check points
Output
Risk management
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Alternatives
Risk management policy
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Technical Design Document
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Specification
Resources
Design in details
Implement methods (工法)
Algorithms
“Project”
Output in each milestone
SOP (optional)
TDD Template
46
Mind Map
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心智圖法
A radiant thinking tool
Applications
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讀書心得
Proposal
上課筆記
遊記
System Analysis
…
Reference
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Programs
 Visio
 MindManager
Books
 Tony Buzan, Barry Buzan
 “The Mind Map Book: How to Use Radiant Thinking to
Maximize Your Brain's Untapped Potential”
47
48
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Mind Map Demo Using MindManager
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Use MindManager X5 pro
Developed by MindJet
50
3rd
The Game Main Loop
51
Win32 Application (1/3)
int APIENTRY WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
...
// register window class
ZeroMemory(&wc, sizeof(WNDCLASSEX));
wc.style
= CS_OWNDC | CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS;
wc.lpfnWndProc = KKMainProc;
...
RegisterClassEx(&wc);
...
// the main loop
KKMainLoop();
// unregister the window class
UnregisterClass(wc.lpszClassName, hInst);
return id;
}
52
Win32 Application (2/3)
LRESULT CALLBACK KKMainProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
LRESULT l = FALSE;
...
// switch for all incoming messages from WindowsXX
switch (uMsg) {
case WM_KEYDOWN:
...
l = TRUE;
break;
...
}
// echo the result
if (l) {
return l;
}
else {
return DefWindowProc(hWnd, uMsg, wParam, lParam);
}
}
53
Win32 Application (3/3)
void KKMainLoop()
{
MSG msg;
BOOL kkBeQuit = FALSE;
// the main loop
while (!kkBeQuit) {
// check window's messages
while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
if (msg.message == WM_QUIT) {
kkBeQuit = TRUE;
}
// invoke the WindowsX to handle the incoming messages
TranslateMessage(&msg);
DispatchMessage(&msg);
}
// do your jobs here, for example, check the timing and do something in regular
...
}
}
54
Event-driven Programming
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Win32 programs are event-driven
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We need an infinitive loop to check all incoming events.
In the loop :
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Messages = events
So as all windows system (for example : X window)
Check if there are incoming events (messages)
Handle the events
Check the time and do something in regular
Incoming events :
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Interrupts
System requests
55
Timers & Events (1/2)
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Timers (do something in regular timing)
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The sub-system to handle timing
Must be precise to at least 1 ms or less
 30fps = 1/30 second = 33.333… ms
On win32 platform, you can use “performance counter” instead of
the win32’s “WM_TIMER” message
 For windows9x, WM_TIMER = 18.2 fps (maximum)
Events
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Input devices
 Mouse
 Keyboard
Something coming from network
System requests
 Re-draw
 Losing/getting the input focus
 …
56
Timers & Events (2/2)
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Two types of jobs (Callbacks) to do (Call) :
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In regular
 Timers callbacks
By requests
 Input device callbacks
So as the game main program
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A game is an interactive application.
 Mouse
 Hotkeys
 Gamepads
A game is time-bound.
 Rendering locked in 30fps or 60fps
 Motion data produced in 30fps
 Game running in 30fps
57
Implement the Timer (1/6)
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On PC platform : use “Performance Counter”
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QueryPerformanceFrequency()
QueryPerformanceCounter()
// timers data structure
typedef struct {
BOOL beAble;
// is the timer is enabled/disabled ?
BOOL be1st;
// is this the 1st time for the timer to be checked
// after last initialization ?
BOOL beLockFps; // is locked on FPS ?
double initTime; // initial time
double timeInv;
// system ticks for one frame
double nxtTime; // next checking time
void (*timer)(int); // timer's callback
double resetTime; // reset time
} TIMERs, *TIMERptr;
58
Implement the Timer (2/6)
/*---------------------------------------------------------------------initialize a timer and bind a user-defined timer callback
------------------------------------------------------------------------*/
void FyBindTimer(DWORD id, float fps, void (*fun)(int), BOOL beLock)
{
if (id < 0 || id >= MAXTIMERS) return;
/* assign the timer's callback */
fyTimer[id].timer = fun;
/* set lock-to-fps flag */
fyTimer[id].beLockFps = beLock;
/* calculate the ticks for one frame */
fyTimer[id].timeInv = (double) (fyFreq) / (double) fps;
fyTimer[id].be1st = TRUE;
fyTimer[id].beAble = TRUE;
}
59
Implement the Timer (3/6)
/*-----------------------------------get current system clock tick
--------------------------------------*/
double FYGetCurrentSystemTick()
{
LARGE_INTEGER timeCount;
/* get current tick */
QueryPerformanceCounter(&timeCount);
return (double) timeCount.QuadPart;
}
/*
// get the system ticks for one second
QueryPerformanceFrequency(&timeFreq);
fyFreq = timeFreq.LowPart;
*/
60
Implement the Timer (4/6)
/*-----------------------------------------------------------invoke the TheFly3D system to handle the timers
--------------------------------------------------------------*/
void FyInvokeTheFly(BOOL beTimer)
{
MSG msg;
if (fyBeQuit) return;
while (!fyBeQuit) {
// check window's messages
while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
if (msg.message == WM_QUIT) fyBeQuit = TRUE;
TranslateMessage(&msg);
DispatchMessage(&msg);
}
// check the timer
if (beTimer && fyBeTimer) FYInvokeTimer();
}
}
61
Implement the Timer (5/6)
/*--------------------check all timers
----------------------*/
void FYInvokeTimer()
{
int i, skipS;
double dTime;
// get current time
dTime = FYGetCurrentSystemTick();
for (i = 0; i < MAXTIMERS; i++) {
if (fyTimer[i].beAble && fyTimer[i].timer != NULL) {
// for the first time .....
if (fyTimer[i].be1st) {
// initialize the timer
fyTimer[i].be1st = FALSE;
fyTimer[i].initTime = dTime;
fyTimer[i].nxtTime = dTime + fyTimer[i].timeInv;
(*(fyTimer[i].timer))(1);
}
62
Implement the Timer (6/6)
else {
if (fyTimer[i].beLockFps) {
if (dTime >= fyTimer[i].nxtTime) {
// calculate skip frames
skipS = (int)((dTime - fyTimer[i].nxtTime) / (double)fyTimer[i].timeInv) + 1;
// get next checking time
fyTimer[i].nxtTime += (double) (skipS * fyTimer[i].timeInv);
// check some abnormal conditions
...
// invoke the timer callback
(*(fyTimer[i].timer))(skipS);
}
}
else {
(*(fyTimer[i].timer))(1);
}
}
}
}
}
63
Game Loop (1/2)

Single player
Loop
Check game over
y
Exit the loop
n
Peek player input
Implement
timer callback
Rendering
64
Game Loop (2/2)

Network client
Loop
y
Check game over
Exit
n
Peek user input
Receive messages
From network
Timer callbacks
Send messages
To network
Rendering
65
Jobs in Regular (In Timers)





Check “Win/Lose”
Check “Quit”
Make objects moving …
Play character’s motion to the next frame
Play animation to the next frame










Models
Textures
…
Perform game logic calculation
Perform geometry associated calculation
 i.e. LOD
Perform AI “Thinking”
Perform collision detection
Perform the 3D rendering
Play FX
…
66
Jobs By Request

Mouse Input





Keyboard Input






Hotkey
Typing
Gamepad


Press/release the mouse button
Drag
Double-click
Move
Same behavior as the hotkey
Except looking not like the keyboard
Network
System
…
67
4th
TheFly3D Game Engine
68
The Main Program
void main(int argc, char **argv)
{
// create the game world & 3D scene
...
// set Hotkeys
FyDefineHotKey(FY_ESCAPE, QuitGame, FALSE);
...
// define some mouse functions
FyBindMouseFunction(LEFT_MOUSE, InitPivot, PivotCam, EndPivot, NULL);
...
// bind a timer for rendering, frame rate = 60 fps
FyBindTimer(0, 60.0f, RenderIt, TRUE);
// bind a timer for game AI, frame rate = 30 fps
FyBindTimer(1, 30.0f, GameAI, TRUE);
// invoke the system
FyInvokeTheFly(TRUE);
}
69
Hotkey Callback
//------------------// quit the game
//------------------void QuitGame(WORLDid gID, BYTE code, BOOL value)
{
if (code == FY_ESCAPE) {
if (value) {
FyWin32EndWorld(gID);
}
}
}
70
Mouse Callback
/*----------------------------------------initialize the pivot of the camera
------------------------------------------*/
void InitPivot(WORLDid g, int x, int y)
{
oldX = x;
oldY = y;
}
/*-----------------pivot the camera
-------------------*/
void PivotCam(WORLDid g, int x, int y)
{
FnModel model;
if (x != oldX) {
model.Object(cID);
model.Rotate(Z_AXIS, (float) (x - oldX), GLOBAL);
oldX = x;
}
if (y != oldY) {
model.Object(cID);
model.Rotate(X_AXIS, (float) (y - oldY), GLOBAL);
oldY = y;
}
}
71
The Timer Callback
//---------------------------------------------------------------------------------------// Render callback which will be invoked by TheFly3D every 1/60 second
//---------------------------------------------------------------------------------------void RenderIt(int skip)
{
FnViewport vp;
FnWorld gw;
// render the scene
vp.Object(vID);
vp.Render(cID, TRUE, TRUE);
// perform double-buffering
gw.Object(gID);
gw.SwapBuffers();
}
72
Introduction to TheFly3D

A real-time 3D graphics programming library


Using C++
Cross-platform




An API for 3D graphics developers
Provide a fundamental scene management system



Scene tree
Built-in visibility culling
According to the experiences from the author, some game
development features are added.




DirectX9.0c
OpenGL 1.5
Characters
Terrain system
…
Current version 0.8a1 (0920, 2005)

Shader has been added in D3D version
73
TheFly3D in A Chart
Game
NPC System
Virtual Agent
Trading System
Combat System
FX System
Terrain
Character Dynamics Sound FX
Collision
3D Scene Mngmt
3D Graphics API
2D Sprite
Game AI
Story
Gamepad
2D API
Hardware
Script System
UI
Audio
Network
Input Device
OS API
Game Play
Layer
Engine
Layer
System
Layer
Developing
Developed
74
Development Environment



.NET2003 Visual C++ 7.1
DirectX9.0c SDK (Dec, 2004)
Two include files : (must!)



TheFly.h
TheFlyWin32.h (Win32 version + D3D)
Linked libraries (API version)

TheFlyLibD_08_01.lib

d3d9.lib d3dx9.lib dsound.lib dxguid.lib winmm.lib
75
Create the Visual C++ Project for “TheFly3D”

Create folders for TheFly3D API







…\include
…\lib
New a Win32 application project
Set the additional include/library directories to TheFly3D
API
Add DirectX 9.0 SDK’s include/lib to additional search
directories
Add d3d9.lib d3dx9.lib dsound.lib dxguid.lib winmm.lib to
additional dependencies
Add TheFly.h, TheFlyWin32.h, TheFly3DLibD_xxxx.lib into
the project
76
The 1st TheFly3D Program – hello.cpp




Create
Create
Create
Create





a 3D world
a viewport
a scene
3D entities
A camera
A teapot model
A light source
Translate the camera to show the model
Bind callbacks to make the program interactive
77
Demo - Hello
Do it!
78
The Basics to Write TheFly3D Program

All Win32 code is transparent.



void main(int argc, char *argv[])
All Win32 & DirectX code are hidden within the engine.
ID & Function class




TheFly3D creates the objects for you.
 Return the object ID
TheFly3D owns the objects.
You have the right to handle the objects.
 Use function classes
No internal data structure & functions revealed
// create a viewport
vID = gw.CreateViewport(ox, oy, ww, hh);
FnViewport vp;
vp.Object(vID);
vp.SetBackgroundColor(0.3f, 0.3f, 0.0f);
79
Initialize TheFly3D

In general the 1st function to use TheFly3D is :



FyWin32CreateWorld()
After the calling successfully, you can get the non-zero ID
(WORLDid) of a world object.
Assign the ID to a world function class object for
manipulating the world.
// create a new world
WORLDid gID = FyWin32CreateWorld(“Tester", 0, 0, 800, 600, 16, FALSE);
FnWorld gw;
gw.Object(gID);
gw.SetTexturePath("Data\\textures");
80
The World in TheFly3D

A world is a set of graphics layers where the 3D objects
acts on.
A World
3D Graphics Layers
Frame Buffers
(front + back)
81
The 3D Graphics Layer


A 3D graphics layer is a projection of the rendering of a 3D
view.
The set of the 3D objects in the view :


We call it the “Scene”.
The projection we call the “Viewport”
Backdrop
Lights
Camera
3D Models
Board
A 3D Scene
82
The Viewports & Scenes



TheFly3D supports the multiple viewports.
A scene can be rendered on different viewports.
Viewports & scenes are created by the world object.
// create a new world
WORLDid gID;
gID = FyWin32CreateWorld(Tester", 0, 0, 800, 600, 16, FALSE);
FnWorld world;
world.Object(gID);
SCENEid sID = world.CreateScene();
VIEWPORTid vID = world.CreateViewport(0, 0, 400, 300);
world.DeleteScene(sID);
world.DeleteViewport(vID);
83
The Scene


A scene is not a “real” 3D object, just a “set” of 3D
objects.
A scene provides multiple rendering groups to handle the
priority sorting for the rendering of 3D objects.




There are three object lists within a rendering group.
 Invisible list
 Opacity list
 Semi-transparent list
The objects are rendered by the order of rendering groups.
In the same rendering group, the opaque objects are rendered first.
And the semi-transparent objects are sorted and rendered from far
to near…
84
The 3D Entities – Objects


A 3D scene is constructed by a set of “objects” which are
the basic entities in a scene.
An object is a carrier to carry real 3D data including :










Model geometry
Camera data
Lighting data
Terrain data
Particle emitters
Forces
Audio
Objects are created/deleted by its host scene.
Objects can be switched between scenes.
Objects should be assigned to a rendering group.
85
The Objects Can …







Can
Can
Can
Can
Can
Can
Can
have shapes (geometric data)
be grouped (hierarchy)
move (transformation)
look alike (clone or data sharing)
perform (animation or deformation)
be affected (lighted, listened)
be changed dynamically (modification)
86
A Scene Object
Hierarchy
Parent Object
Parameters
Etc
Transformation
Move
Animation
Motion Data
Shape
Geometric Data
Clone
87
A Model Object



An object to carry a set of geometry data is a model
object
You can load the model data from files.
TheFly3D loads .cw3 model files in default.
// create 3D entities
nID = scene.CreateObject(ROOT);
FnObject model;
model.Object(nID);
// load a teapot
model.Load("Teapot.cw3");
88
TheFly3D Scene Tree
A tree-based representation
 Simplified scene graph

Root
89
TheFly3D Scene Tree Is Simplified Scene Graph


A tree-based representation
Simplified scene graph
Root
90
Object Hierarchy
nID = scene.CreateObject(ROOT);
cID = scene.CreateCamera(ROOT);
FnObject model;
model.Object(nID);
model.SetParent(cID);
cID
nID
91
Clone a Model Object
OBJECTid nID = scene.CreateObject(ROOT);
FnObject model;
model.Object(nID);
OBJECTid nID1 = model.Instance();
nID
nID1
Data
instance
92
TheFly3D Major Model Object Functions (1/2)



void model.SetParent(parent_object_ID);
void model.Show(be_show);
void model.SetOpacity(opacity);


void model.SetRenderMode(mode);





mode = WIREFRAME or TEXTURE
OBJECTid clonedID = model.Instance();
void model.ChangeScene(sID);
BOOL model.Load(char *file);


opacity = 0.0 – 1.0
Load a .cw3 model file to a model object
void model.ShowBoundingBox(beShow);
void model.Translate(x, y, z, op);
93
TheFly3D Major Model Object Functions (2/2)

model.SetRenderOption(item, value);

(item, value) =
 (Z_BUFFER, TRUE/FALSE)
 (Z_BUFFER_WRITE, TRUE/FALSE)
 (ALPHA, TRUE/FALSE)
 Add/remove the model to/from alpha sorting list
 (FOG, TRUE/FALSE)
 (SPECULAR, TRUE/FALSE)
 (LIGHTING, TRUE/FALSE)
 (ANTIALIASING, TRUE, FALSE)
 (SOURCE_BLEND_MODE BLEND_ZERO / BLEND_ONE /
BLEND_SRC_COLOR / BLEND_INV_SRC_COLOR /
BLEND_SRC_ALPHA / BLEND_INV_SRC_ALPHA /
BLEND_DEST_ALPHA / BLEND_INV_DEST_ALPHA /
BLEND_DEST_COLOR / BLEND_INV_DEST_COLOR /
BLEND_SRC_ALPHA_SAT / BLEND_BOTH_SRC_ALPHA /
BLEND_BOTH_INV_SRC_ALPHA)
 (DESTINATION_BLEND_MODE values are same as the
SOURCE_BLEND_MODE)
94
Coordinate System

Every model should have its own local coordinate system.



To its parent model, it is in the global space.


Local space
Model space
 The space when it’s modeled
Global space
 The space for reference
World space

The global space of the “Root”
z
Z
Y
X
y
x
95
Transformation

Three basic linear transformations used in TheFly3D.




Translate
Rotate
Scale
Principles :



Right-handed rule
v’ = v M0 M1
Matrix in 12-element (I call the M12)
Rotation matrix
Translation vector
a0
a3
a6
a9
a1 a2 0
a4 a5 0
a7 a8 0
a10 a11 1
96
Translation
model.Translate(dx, dy, dz, op);
x’ = x + dx
y’ = y + dy
z’ = z + dz
T =
1
0
0
dx
0
1
0
dy
(dx dy dz)
0
0
1
dz
97
Rotation
i.e. rotate with z axis
model.Rotate(Z_AXIS, 30.0f, op);
x’ = x cosq – y sinq
y’ = x sinq + y cosq
z’ = z
Rz =
cosq
-sinq
0
0
sinq
cosq
0
0
0
0
1
0
z
y
x
98
Scaling
model.Scale(sx, sy, sz, op);
x’ = x * sx
y’ = y * sy
z’ = z * sz
T =
sx
0
0
0
0
sy
0
0
0
0
sz
0
99
Matrix Operations

Matrix operation

Z
REPLACE, LOCAL, GLOBAL
Y
op = LOCAL
X
op = REPLACE
[ML] [M] [MG]
z
x
y
op = GLOBAL
Object Transformation Matrix
100
TheFly3D Model Transformation Functions

model.Translate(x, y, z, op);


model.Rotate(axis, angle, op);






w : the scalar part of the quaternion
x, y, z : the vector part of the quaternion
The quaternion should be a unit quaternion
op = LOCAL, GLOBAL, or REPLACE
model.SetMatrix(M12, op);



op = LOCAL, GLOBAL, or REPLACE
model.Quaternion(w, x, y, z, op);


op = LOCAL, GLOBAL, or REPLACE
axis = X_AXIS, Y_AXIS, Z_AXIS
model.Scale(sx, sy, sz, op);


op = LOCAL, GLOBAL, or REPLACE
M12 : an M12 matrix
op = LOCAL, GLOBAL, or REPLACE
float *model.GetMatrix();

Get the pointer of the model object’s matrix
101
Transformations vs Movements
Transformation is the term used in
computer graphics but not friendly for
games.
 We use movements to control the 3D
objects moving around in the scene.







Move forward
Move right
Move up
Turn right
Turn left
…
Turn right / left
Move up
Move right
Move forward
102
Facing Direction and Up Direction
Each object is modeled with a facing direction and up
direction “visually”
 In TheFly3D, we use –y axis as the default facing direction
for a model, z axis as the default up direction
 But for a camera :



-z axis is the facing direction
y axis is the up direction
z
y
x
z up + facing to -y
103
Move Forward (1/2)
new position = old position +
distance *(facing direction in unit)
104
Move Forward (2/2)
The object has a local coordinate system.
 Align a local axis of the object with the facing direction
 Make a translation to move the object align the local
axis
 Apply the matrix first before to apply the existing
transformations (op = LOCAL)
 Then the object is moving forward!

FnObject model;
model.Object(nID);
model.Translate(0.0f, -dist, 0.0f, LOCAL); // facing to -y
105
Turn Right/Left (1/2)

An example : (rotate with an arbitrary axis)
-1
-1
-1
M = T1 * R1 * R2 * Rx(angle) * R2 * R1 * T1
T1 = / 1 0 0
0 1 0
0 0 1
-x -y -z
0
0
0
1 /
R1 = / cs2 -sn2 0 0
-z
sn2 cs2 0 0
0
0 1 0
0
0 0 1 /
R2 = / cs1 0 -sn1 0
y
0 1
0 0
sn1 0 cs1 0
0 0
0 1 /
Rx = / 1
0 0 0
0 cs sn 0
0 -sn cs 0
0
0 0 1 /
106
Turn Right/Left (2/2)
The object has a local coordinate system
 Align a local axis of the object with the up direction
 Make a rotation matrix to turn the object along the local
axis
 Apply the matrix first before to apply the existing
transformations
 Then the object is turning !

FnObject model;
model.Object(nID);
model.Rotate(Z_AXIS, -angle, LOCAL); // turn right
107
Terrain




A terrain is a place for 3D objects to walk on
A terrain can be generated from a model file
Neighboring triangles are the next searching target for
current triangle for terrain following
A terrain for terrain following is not the same as the
terrain in visual
108
Generate Terrain in TheFly3D
// create a terrain object
tID = scene.CreateTerrain();
FnTerrain t;
t.Object(tID);
// load a terrain model (just like a regular object)
// but a terrain is invisible in default
t.Load("test_terrain_following.cw3");
// generate the neighboring data for terrain following
// otherwise, the terrain model is for visual only
t.GenerateTerrainData();
109
Put a Model on Terrain Using TheFly3D
// if tID is the terrain object (OBJECTid)
// load a model
OBJECTid nID = scene.CreateObject(ROOT);
FnObject obj;
obj.Object(nID);
// put the model on terrain
float pos[3];
pos[0] = x;
pos[1] = y;
pos[2] = 10000.0f; // should be higher than the terrain!
obj.SetPosition(pos);
obj.PutOnTerrain(tID, be3D, offset, rangeF, rangeB, angle);
110
Terrain Following
Terrain Following (3D)
offset
Terrain Following (2D)
offset
111
Probe for a Model on Terrain
probeBack
probeFront
: terrain following check point
112
TheFly3D Model Movement Functions (1/3)

void model.GetPosition(pos)


void model.GetDirection(faceDir, upDir)


The position is related to its parent object
void model.SetDirection(faceDIr, upDir)


If you just want to get one of the directions, just send NULL pointer
to the one that you do not want to query
void model.SetPosition(pos)


pos is a 3D vector to get the position of the model object
If you just want to set one of the directions, just send NULL pointer
to the one that you do not want to set
Void model.SetDirectionAlignment(fDAxis, uDAxis)

You can change the local axes for facing and up directions
113
TheFly3D Model Movement Functions (2/3)

BOOL model.PutOnTerrain(tID, be3D, offset, probeFront,
probeBack, probeAngle, hightLimit)






tID is a terrain object
be3D = TRUE for 3D terrain following
Offset is the height above the terrain
hightLimit is the terrain following height limit
Return TURE if you successfully put the model on a terrain
int model.MoveForward(dist, beTerrainFollow, be3D, offset)



If you just want to move the model forward but not on terrain, set
beTerrainFollow to FALSE
You should put a model on terrain first. Then you can move it forward
on terrain.
Return value :
 WALK (ok for moving)
 BOUNDARY (hit the terrain boundary)
 BLOCK (not implemented yet, for collision)
 DO_NOTHING (something wrong …)
114
TheFly3D Model Movement Functions (3/3)

int MoveRight(dist, beTerrainFollow, be3D, offset)


void model.TurnRight(float angle)


Same as the MoveForward except moving in right-hand direction
Angle is in degree format
int model.GetCurrentTerrainTriangle()

Get current triangle ID in terrain, where the model is standing
115
A Character
116
Character with motion
117
Introduction to Characters


The characters are the actors of the games.
Three types of characters implemented in games :





Segmented
Mesh
Bone-skin
Root-base concept
Production :


3D animation tools
Motion capture (MoCap)
 For motion data
Base
118
A Segmented Character

A character is composed by a set of models with motion
data to simulate a live creature in real world

Benefits



Hierarchical structure
Easy to implement in a scene tree
Drawbacks

Segment-like
119

The scene tree of a segmented character :
head
up arm
hand
body
fore arm
groin
Base
thigh
groin
foot
shin
body
head
thigh_r
thigh_l
up_arm_r
shin_r
up_arm_l
shin_l
fore_arm_l
hand_l
fore_arm_r
hand_r
foot_r
foot_l
120
A Mesh Character

Vertex animation on skins



Benefits



Animated positional data on skins
3D warping
Easy to implement
Flexible mesh in animation
Drawbacks
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No hierarchy
Each frame is independent.
Massive dataset
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A Bone-skin Character
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Bone-skin skeleton
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Hierarchical bones
Skin deformation run-timely
Benefits
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Bone A
Hierarchical structure
Not segmented look
Drawbacks
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More complicated than the other solutions
Skin deformation need more CPU cost than
transformation only
Skin
Bone B
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Motion Production – by 3D Animation Tools (1/2)
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Keyframe system
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3ds MAX
Softimage
Maya
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Motion Production – by 3D Animation Tools (2/2)
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Low cost (relatively)
Easy to combine animations
Hand-made animations
Hard to make “good” motions
Long production time
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Motion Production – by Motion Capture (1/2)
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Motion Capture
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“MoCap” in short
Types :
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Optical
Magnetic
...
125
Motion Production – by Motion Capture (2/2)

Expensive solution
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Every frame is a keyframe
Very live motion
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Noise !
Need post-processing for games
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Hardware and software
Pathing the data
Re-keyframing
Cleaning noise
Re-targeting
Hard to combine motions
126
The Root-Base Concept (1/2)
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Use root-base structure to construct the character
Base
Root
(groin)
Base
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The Root-Base Concept (2/2)
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A character has some models to be the geometry roots of
the character system.
The root plays as the gravity center of the character.
The root can be translated and rotated.
The others are joints.
The joints can rotate only.
A ghost object is added to be the parent of the root, which
is the base of the character.
The base is the center for the character’s movement.
We move the base to perform character’s moves.
128
Motion Data - Pose
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A set of frames to describe a character’s motion
For examples : Walk, run, attack, …
Keyframed or non-keyframed
Motion data in
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Position (pivot) + quaternion
Position (pivot) + Euler angles
Position (pivot) + (q, n)
Matrix
walk
run
attack
fall
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Load a Character
FnScene scene;
CHARACTERid actorID;
.cwc is a character
description file.
scene.Object(sceneID);
actorID = scene.LoadCharacter(“fm.cwc");
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Play a Pose
BLENDTREEid btID = actor.GetBlendTree();
FnBlendTree bt;
bt.Object(btID);
// the 2nd motion definition
BLENDNODEid aaaID;
aaaID = bt.CreateAnimationNode(2);
// start to play a pose (1st time)
actor.PlayBlendNode(aaaID, (float) 0, START, TRUE);
// continue to play a pose
actor.PlayBlendNode(CURRENT, (float) skip, LOOP, TRUE);
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Make a Character to Move Forward
FnCharacter actor;
// play walking pose
actor.Object(actorID);
actor.PlayBlendNode(CURRENT, (float) skip, LOOP, TRUE);
// move it forward
actor.MoveForward(dist, beTF, be3D, offset);
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TheFly3D Character Movement Functions (1/2)
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void actor.GetPosition(pos)
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void actor.GetDirection(faceDir, upDir)
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The position is related to its parent object
void actor.SetDirection(faceDIr, upDir)
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If you just want to get one of the directions, just send NULL pointer
to the one that you do not want to query
void actor.SetPosition(pos)
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pos is a 3D vector to get the position of the character
If you just want to set one of the directions, just send NULL pointer
to the one that you do not want to set
BOOL actor.PutOnTerrain(tID, be3D, offset, probeFront,
probeBack, probeAngle, hightLimit)
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tID is a terrain object
be3D = TRUE for 3D terrain following
Offset is the height above the terrain
hightLimit is the terrain following height limit
Return TURE if you successfully put the character on a terrain
133
TheFly3D Character Movement Functions (2/2)
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void actor.MoveForward(dist, beTF, be3D, offset)
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If you just want to move the character forward but not on terrain,
set beTF to FALSE
You should put a character on terrain first. Then you can move it
forward on terrain.
A character is always using his local -y-axis as facing direction
void actor.TurnRight(float angle)
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Angle is in degree
A character is always using his local z-axis as up direction
134
TheFly3D Character Functions
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OBJECTid actor.GetBaseObject()
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OBJECTid actor.GetObjectByName(name)
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The function is to play the motion for a specific frame
Set beIncludeBase = TRUE to play the base object’s motion
BLENDTREEid actor.GetBlendTree()
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You can get the each model part of the character by its name in
character file
For a bone-skin character, this function can get the bones in the
skeleton
BOOL actor.PlayFrame(frame, beIncludeBase)

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You can get the base object of the character
Get the character’s blend tree data
You can define all poses in a blend tree (blend nodes)
float actor.PlayBlendNode(btNodeID, skipFrame, mode,
beIncludeBase)
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All poses for a character is defined as a blend node
Skip frames can be floating-point
Mode can be ONCE or LOOP!
135