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• Computer graphics


  The art of drawing pictures on computer screens with the help of programming
• Computer graphics


  • Refers to any computer device or program that makes a computer capable of displaying and manipulating pictures
  • Involves computations, creation, and manipulation of models and images
  • Describes any use of computers to create and manipulate images
  • A rendering tool for the generation and manipulation of images
• Pixel


  The smallest addressable graphical unit represented on the computer screen
• Aim of computer graphics

  • To produce realistic and/or useful images on a computer
  • For some applications the emphasis will be on realism (e.g. special effects in films), whereas for others it will simply be on usefulness (e.g. data visualisation)
  • The final image will be generated from some model of the scene we want to take a picture of
• Object model


  Typically represents the geometry of the object
• Rendering


  1. Starting with a model (often a 3-D model) of the world and taking a picture of it with a camera

  2. Includes hidden surface elimination

  3. Includes clipping (removing objects or parts of objects outside of the visible area of a computer screen or viewport)
• Evan Sutherland developed the first computer graphics design system (Sketchpad) at MIT


  1963
• Major areas of computer graphics

  • Modeling
  • Rendering
  • Animation
• Modeling


  Deals with the mathematical specification of shape and appearance properties in a way that can be stored on the computer
• Rendering


  The creation of shaded images from 3D computer models
• Animation


  A technique to create an illusion of motion through sequences of images
• Types of computer graphics based on interaction

  • Interactive graphics
  • Non-interactive graphics
• Interactive graphics


  Images need to be generated in real-time and the user can interact with the model of the world using specialized input hardware
• Non-interactive graphics


  The picture is produced on the computer screen in a fixed format, and the user does not have any control over the image
• Types of computer graphics based on object type

  • 2D graphics
  • 3D graphics
• 2D graphics


  Objects or images with two dimensions (length and width) that appear flat on the screen and are viewed from only one angle
• 3D graphics


  • Create the illusion of depth in addition to length and width, despite the fact that they are technically still flat images on a screen
  • Built around a wireframe mesh-like model of lines that create geometric shapes, such as spheres, around which texture and color are applied
• Types of computer graphics based on drawing method

  • Raster graphics
  • Vector graphics
• Raster graphics


  Build up the pictures by scanning beams of electrons back and forth from top to bottom and left to right like a kind of instant electronic paintbrush
• Raster graphics


  • Simple to use, but don't scale up to different sizes very well and the image becomes noticeably more grainy and pixelated
  • Require a huge amount of memory
• Vector graphics


  Drawing with straight lines and curves instead of individual dots, which means we can produce an image more quickly and store it with less information
• Vector graphics


  • Best for printing since they are composed of a series of mathematical curves
• The main difference between vector and raster graphics is that raster graphics are composed of pixels, while vector graphics are composed of paths (which are defined by a start and end point)
• Simple computer graphic programs like Microsoft Paint and Paint Shop Pro are based on raster graphics, while more sophisticated programs such as CorelDraw, AutoCAD, and Adobe Illustrator use vector graphics
• Common uses of computer graphics


  • Communication
  • Animation
  • Digital photography, film and television, video games, and on electronic devices
• Applications of computer graphics

  • Graphs and charts
  • Computer-Aided Drafting and Design (CAD/CADD)
  • Data visualisation
  • Virtual Reality and Augmented Reality
  • Education and training
  • Graphical User Interfaces
  • Entertainment
• Computer graphics is also used in office automation and desktop publishing, process control, cartography, and image processing