1. 網路與多媒體實驗 專題報告 電機四 陳人豪

2. Outline History of computer graphics Computer graphics pipeline Introduction to animation

3. History 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

4. History SAGE system, WWII  Air defense system Dr. Ivan Sutherland (MIT), 1963  Invent Sketchpad  Interactive design on vector graphics  The origin of computer graphics 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

5. History First raster display, 1966  What is raster scan?  Display or capture image line by line 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

6. History Apple II, 1977  帶起 PC 革命  彩色圖形介面 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

7. History Tron, 1982, Disney  中文翻譯 “ 電子世界爭霸戰 ”  第一部運用動畫手法拍攝的電影  創造了電影史上第一個數位角色 “Tron”  在迪士尼頻道有播出過 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

8. History Toy Story, 1995, Pixar  第一部 3D 動畫長片  Woody 跟 Buzz Lightyear 之間 的愛恨情仇 萌芽期 (60’s~mid 70’s) 發展期 (late 70’s~80’s) 成熟期 (90’s~00’s)

9. History 目前在許多領域都有發揮  Interactive environment  Scientific & medical visualization  Arts  …

10. Computer Graphics Pipeline

11. Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display

12. Computer Graphics Pipeline : Modeling Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display Object spaceWorld space 原本在不同 object space 中的 model 轉 換至同一座標系 (world space) Transformation example: Translation, Scaling, Rotation, Projection, 或者以 上的綜合

13. Computer Graphics Pipeline : Illumination Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display 根據材料性質、物體表面性質以及光 源性質來實作 Local lighting model example: Diffuse, Ambient, Phong…

14. Computer Graphics Pipeline : Transformation Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display World space Eye space 將 world space 對應到 eye space 通常將 viewing position 對應到 eye space 的原點

15. 將視角之外的物件部份消除掉  類似窗戶跟景物的關係 可節省系統運算資源 Several clipping algorithms have been devised Hidden Surface Removal Problem Computer Graphics Pipeline : Clipping Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display

16. Computer Graphics Pipeline : Projection Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display Screen Space 將在 eye space 中 3D 的物件轉換至 2D 的 screen space 上 Eye space

17. Computer Graphics Pipeline : Rasterization Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display 將物件影像像素化 插入顏色、深度等變數

18. Computer Graphics Pipeline : Display Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display 三種主要輸出裝置：  Monitors (CRT)  Flat Panel Display (LCD, plasma)  Hard Copy 兩個主要考慮的問題  色彩校準  人的相對亮度感覺

19. 經過多次的 transformation … Modeling Transformations Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion (Rasterization) Visibility / Display Object space World space Eye Space / Camera Space Screen Space

20. Computer Animation

21. Introduction to computer animation Keyframing Procedural animation Motion capture

22. Keyframing Draw key frames Tweening  Filling in-betweens  Frames/sec depending on speed of movements

23. Keyframing Linear Interpolation Non-linear Interpolation Others Linear InterpolationNon-linear Interpolation

24. Procedural Animation 使用複雜的演算法來達成動畫效果 Example  Special effects: explosions, water, particles…  Visualization 可重複使用 精確度較 keyframing 高

25. Motion Capture Application  Movies  Games Games  Virtual Reality

26. Motion Capture Actors wearing sensors Tracking camera ? Sampling Processing Output exampleexample2

27. Motion Capture Types of sensors  EM position and orientation sensor Require a wire to each sensor Limited working volume Readings can be distorted by EM fields  Ultrasonic rangefinder triangulation Cheaper but less accurate  Optical triangulation Reflective or emissive markers attached to objects Two cameras triangulate position triangulation

28. Motion Capture: The Processing Stage ReconstructionLabelingEditing ActorisationCharacterizationPost-animation

29. Motion Capture Advantage  Exactly animate human movements  Can capture secondary animation  Can capture difficult-to-model physical movement (ex. 雙截棍 )  Allow one actor to play multiple role in a film

30. Motion Capture Disadvantage  Noise!!!  Magnetic system interference  Difficult to manipulate the data after capturing & processing  Expensive  Difficult to cooperate with cartoon models

31. Computer Animation: Future The old vs. the new

32. The end Coming up next… 高新綸