COMPUTER GRAPHICS

Computer graphics are graphics created using computers and the representation of image data by a computer specifically with help from specialized graphic hardware and software. The interaction and understanding of computers and interpretation of data has been made easier because of computer graphics. Computer graphic development has had a significant impact on many types of media and have revolutionized animation, movies and the video game industry.

The phrase “Computer Graphics” was coined in 1960 by William Fetter, a graphic designer for Boeing.The field of computer graphics developed with the emergence of computer graphics hardware. Early projects like the Whirlwind and SAGE Projects introduced the CRT as a viable display and interaction interface and introduced the light pen as an input device. A programmer for the Whirlwind SAGE system performed a personal experiment in 1954 in which a small program he wrote captured the movement of his finger and displayed it`s vector (his traced name) on a display scope. The same individual, Douglas T. Ross, working at MIT on transforming mathematic statements into computer generated machine tool vectors in 1959 took the opportunity to create a display scope image of a Disney cartoon character.

This course offers an in-depth exploration of fundamental concepts in 2D and 3D computer graphics. After introducing 2D raster graphics techniques, the course focuses on 3D modeling, geometric transformations, 3D viewing and rendering.

This is an introduction to the foundations of 3-dimensional computer graphics. Topics covered include 2D and 3D transformations, interactive 3D graphics programming with OpenGL, shading and lighting models, geometric modeling using Bézier and B-Spline curves, computer graphics rendering including ray tracing and global illumination, signal processing for anti-aliasing and texture mapping, and animation and inverse kinematics. There will be an emphasis on both the mathematical and geometric aspects of graphics, as well as the ability to write complete 3D graphics programs.

Characteristics of Graphics Displays

• Addressable points: The co-ordinate system used by the display in terms of addressable points in the X direction (horizontal) and Y direction (vertical).
• Resolution: The smallest point which can be resolved from any other. This is effected by not only the number of addressable points but also the quality of the CRT. If the CRT system is of poor quality the minimum dot size may be larger than the difference between two addressable points. Attempts to use normal TV sets for graphics terminals often leads to loss of resolution, e.g. normal ‘every day’ TV scenes do not need as high resolution as a line drawing generated on a computer.
• Aspect ratio: The ratio of X co-ordinates per unit length to Y co-ordinates per unit length. Ideally for computer graphics such be 1:1 but is often not.
• Linearity: In practice a linear system is desired, i.e. the addressable points per unit length of the screen is constant for each axis.
• Convergence: This effects colour systems in that the linearity of each colour circuit is not identical. If a white grid is drawn over the screen lines ,near the edges, it breaks into individual red, green and blue colours.
• Random-vector display: The electron beam may be directed to any random point on the screen under program control. The display frame is created by moving the beam over the screen in the pattern of the image to be created.
• Raster display: The display frame is created by the beam being moved in a fixed raster pattern of the screen with appropriate points of each line illuminated to give the impression of continuous vectors, etc.

Computer Graphics Contents

• Introduction
• CRT Display Devices
• Transformations in 2D
• Three Dimensional Graphics
• Projection Transformations And Viewing Pipeline
• 3D Viewing - Projection Transformations And Viewing Pipeline
• Scan Converting Lines, Circles And Ellipses
• Polyfill- Scan Conversion Of A Polygon
• Scan Conversion Of A Polygon
• Clipping - Lines And Polygons
• Clipping Lines
• Solid Modelling
• Visible Surface Detection
• Illumination And Shading
• Curve Representation
• Curves And Surface Representation
• Graphics Programming Using Open GL
• Advanced Topics: Anti Aliasing, Color, Soft Objects, Animation, Visual Effects, System Architectures