SCI 3750 Computer Graphics and Animation

1
SCI 3750 Computer Graphics and Animation
Lecturer Dr. P C Yuen, RRS 723 Text Intera
ctive Computer Graphics Angel, Edward Addison
Wesley 2000 ISBN 0-201- 38597-X Website
http//www.comp.hkbu.edu.hk/sci3750/
2
Computer Graphics
Computer graphics is the discipline concerned
with all aspects of producing pictures or images
using a computer. Interactive computer graphics
implies user is in the loop of feedback process
Graphics System
User
React to Change
Display
Change Image
Input Device
3
History of Computer Graphics

• Computer Aided Design (CAD) 1965
• Simulators (1975-)
• Interactive raster graphics (80s)
• Virtual reality (late 80s - )
• Computer animation
• Visualization
• Computer art
• Web/Internet based graphics

4
Applications of Computer Graphics

• Display of Information
• Medicine, Scientific Visualization
• Design
• CAD/CAM
• Simulation
• Flight simulators, Virtual reality, Entertainment
  applications
• User Interface
• GUI, Augmented reality, Games interface

5
Computer Graphics vs Image Processing

• Image Processing
• Input a real image
• Output objects model

• Computer Graphics
• Input objects model
• Output realistic image

A sequence of images (frames)
Pictures that move
Computer Animation
Video Processing
6
Goals in Computer Graphics and Animation

• Computer Graphics To generate photo-realistic
  images
• 2D graphics, Modeling, rendering, colour,
  Projection etc
• Computer Animation To generate motion-realistic
  video
• 3D modeling, Geometric transformation, motion etc

7
The Human Visual System vs The Pinhole camera
Visible Spectrum
Human Visual System
Pinhole camera
8
The Synthetic-camera Model
9
Clipping
10
Graphics Conceptual Model
Real Light
Human Eye
Real Object
Human Eye
Graphics System
11
Pixels and Image
12
Ray Tracing with Single Point Source
13
Ray Tracing with Multiple Light Sources
14
RGB Color Space
G
Green (0,1,0)
Yellow (1,1,0)
White (1,1,1)
Cyan (0,1,1)
Red (1,0,0)
R
Blk
Blue (0,0,1)
Magenta (1,0,1)
B
15
Additive Color
Red
Yellow
Magenta
White
Cyan
Blue
Green
16
Computer Graphics Conceptual Model
Output Devices
Application Program
Application Model
Graphics System
Input Devices
17
Modeling-Rendering Pipeline
18
Computer Graphics Terminology

• Rasterization
• Convert the mathematical description of objects
  and their associated colour information to pixels
  on the screen
• Rendering
• A process by which a computer creates images from
  models
• The models, or objects, are constructed from
  geometric primitives, such as points, lines and
  polygons, which are specified by vertices.
• The rendered image consists of pixels drawn on
  the screen.

19
Geometry Pipeline