網路與多媒體實驗 專題報告

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. Computer Graphics Pipeline 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 • 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 Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion(Rasterization) Object space World space Visibility / Display

13. Computer Graphics Pipeline : Illumination Modeling Transformations • 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… Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion(Rasterization) Visibility / Display

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

15. Computer Graphics Pipeline : Clipping Modeling Transformations • 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 Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion(Rasterization) Visibility / Display

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

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

18. Computer Graphics Pipeline : Display Modeling Transformations • 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 Illumination (Shading) Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Scan Conversion(Rasterization) Visibility / Display

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

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 Interpolation Non-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 • Virtual Reality

26. Motion Capture Actors wearing sensors Tracking camera ? Sampling Processing Output example example2

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 Reconstruction Labeling Editing Actorisation Characterization Post-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