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CHAPTER ONE Introduction to Interactive Computer Graphics and Graphics hardware 1 11/27/2023 Course Contents  Chapter One  Introduction to Interactive Computer Graphics and Graphics hardware  W...

CHAPTER ONE Introduction to Interactive Computer Graphics and Graphics hardware 1 11/27/2023 Course Contents  Chapter One  Introduction to Interactive Computer Graphics and Graphics hardware  What is Graphics  Common Uses of Computer Graphics  Brief History of Computer Graphics  Application Area  Graphics hardware  Raster Display Systems  Introduction To The 3D Graphics Pipeline  The Z-Buffer For Hidden Surface Removal 2 11/27/2023 What is Computer Graphics  Computer graphics is the display, storage & manipulation of images and data for the visual representation of a system.  Computer graphics is an art of drawing pictures, lines, charts, etc. using computers with the help of programming.  Computer graphics refers to the creation, storage and manipulation of pictures and drawings using a computer.  Computer graphics is made up of number of pixels. 3 11/27/2023  Computer graphics has became an efficient tool for presentation of information in such divers field as science, engineering, medical science , business, industry ,art, entertainment, advertisement, education and training etc 4 11/27/2023 Cont..  Computer Graphics is the creation of pictures with the help of a computer.  The end product of the computer graphics is a picture it may be a  business graph,  drawing,  engineering.  Etc.… 5 11/27/2023 Computer Graphics  The aim of computer graphics is 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).  Computer graphics provides methods to generate images using a computer.  The word “image” should be understood in a more abstract sense here. 6 11/27/2023 Cont..  An image can represent a realistic scene from the real world, but graphics like histograms (statics diagram) or pie charts as well as the graphical user interface of a software tool are also considered as images.  The development of computer graphics has made computers easier to interact with, and better for understanding and interpreting many types of data. 7 11/27/2023  Cont...  Developments in computer graphics had a profound impact on many types of media and have revolutionized animation, movies and the video game industry.  The term computer graphics refers to several different things:  the representation and manipulation of image data by a computer  the various technologies used to create and manipulate images  the images so produced, and  the sub-field of computer science which studies methods for digitally synthesizing and manipulating visual content. 8 11/27/2023 Interactive Computer Graphics  In interactive Computer Graphics user have some controls over the picture, i.e., the user can make any change in the produced image  Interactive Computer Graphics require two-way communication between the computer and the user.  A User can see the image and make any change by sending his command with an input device. 9 11/27/2023 Components of Interactive graphics  It consists of three components: 1. Frame Buffer or Digital Memory 2. A Monitor likes a home T.V. set without the tuning and receiving electronics. 3. Display Controller or Video Controller:  It passes the contents of the frame buffer to the monitor. 10 11/27/2023 Common Uses of Computer Graphics 11 11/27/2023  History of Computer Graphics(Reading Assignment) 1950: The first graphic images are created by Ben Laposky using an oscilloscope to generate waveform artwork produced by manipulating the analog electronic beams. 1951: Designed to support military preparedness, Jay Forrester and Robert Everett of the Massachusetts Institute of Technology (MIT) produce the Whirlwind, a mainframe computer with a CRT to plot blips representing incoming aircrafts based on radar-gathered 12 data. 11/27/2023  History of Computer Graphics 1955: Direct descendant of the Whirlwind, the SAGE (Semi- Automatic Ground Equipment) air defense system is designed by Bert Sutherland at MIT. It uses simple vector graphics to display on analog CRTs radar images with a wireframe outline of the region being scanned, as well as the first light pen as an input device that operators would use to pinpoint planes flying over regions of the United States. It becomes a key part of the US missile defense system. 13 11/27/2023  History of Computer Graphics 1959: General Motors and IBM develop “DAC-1” (Design Augmented by Computers), the first industrial CAD system (Computer-Aided Design) used to help engineers design cars. It allows a user to rotate and view a simple drawings. 1960: The term “computer graphics” is coined by William A. Fetter at Boeing to describe the new design methods for his human factors cockpit simulations. Two years later, he will create the “First Man” digital human for cockpit studies. 14 11/27/2023  History of Computer Graphics 1961: Spacewar, the first video game, is developed by MIT student Steve Russell for the DEC PDP-1 minicomputer. 1963: For his doctoral thesis at MIT, Ivan Sutherland develops Sketchpad, the first Computer-Aided Drafting and Design (CADD) package allowing shapes to be interactively drawn on a vector-based display monitor using a light pen input device wired into the computer. The light pen uses a small photoelectric cell in its tip to emit an electronic pulse when the pen “sees” the electron beam. 15 11/27/2023  History of Computer Graphics 1963: Larry Roberts develops the first effective hidden-line removal algorithm, the precursor to various subsequent hidden-line and hidden-surface algorithms. 1963: The mouse is invented by Doug Englebart at the Stanford Research Institute (SRI). 1965: The digital line drawing algorithm for raster devices developed in 1962 by Jack Bresenham at IBM is published. 1966: Ivan Sutherland creates the first head-mounted display, the Sword of Damocles, which displays separate wireframe images, allowing depth perception. 16 11/27/2023 History of Computer Graphics 1967: MIT’s Center for Advanced Visual Studies is founded by Gyorgy Kepes. 1967: Don Greenberg starts a program at Cornell. 1968: Dave Evans joins the computer science department at the University of Utah and forms a CG group. Sutherland also joins the University of Utah. 1968: Frustrated by the lack of graphics hardware available, Evans & Sutherland then found their own company. 1968: Intel is founded. 17 11/27/2023 History of Computer Graphics 1968: Arthur Appel at IBM introduces ray-casting, a pre- cursor to ray-tracing which combines a hidden-surface and shadow algorithm. 1969: Initiated by Sam Matsa and Andy vanDam, ACM creates a special interest group on graphics, SIGGRAPH. The first SIGGRAPH conference held in Boulder in 1973 counts 1,200 attendees versus about 20,000 nowadays. 1969: At the Palo Alto Research Center (PARC) of Xerox, Utah alumni Alan Kay develops the concept of Graphical User Interface (GUI). 1969: The first framebuffer (with 3 bits per pixel) is built at Bell Labs, initiating the transition from vector graphics, i.e. drawing lines between coordinates, to raster video displays containing a value for each pixel on the screen, transforming vector representations into raster format images. 18 11/27/2023 History of Computer Graphics 1971: Gouraud shading is developed by Utah student Henri Gouraud. By interpolating intensity, visual improvements over flat shading may be achieved at a marginal cost. 19 11/27/2023 History of Computer Graphics 1973: The entertainment feature film Westworld makes the first use of 2D animation, while 3D wireframe CGI will first be used 3 years later in its sequel Futureworld. 20 11/27/2023  History of Computer Graphics 1974: Wolfgang Strasser in his dissertation describes the Z- Buffer, together with Jose Encarnacao he can be seen as the fathers of CG in Germany 1974: Utah student Edwin (Ed) Catmull (now president of Walt Disney Animation Studios) develops both the Z-buffer hidden-surface algorithm as well as texture mapping. 21 11/27/2023  History of Computer Graphics 1974: Alexander (Alex) Schure, founder of the New York Institute of Technology (NYIT), creates a new Computer Graphics Lab, naming Ed Catmull director. Joined by Alvy Ray Smith and others, the team develops interest in producing what could have been the first feature- length CGI film, The Works, but it was never completed. 22 11/27/2023  History of Computer Graphics 1975: Utah student Bui Tuong Phong develops a specular illumination model. He also introduces the interpolation of normals for shading, now known as Phong shading. 23 11/27/2023  History of Computer Graphics 1975: At IBM, mathematician Benoit Mandelbrot introduces geometry of fractional dimension. Fractals are used in computer graphics to create realistic simulations of natural phenomena such as mountains, coastlines, wood grain… 24 11/27/2023  History of Computer Graphics 1975: Using Bezier patches, Utah student Martin Newell creates a 3D computer model of a physical teapot, now at the Computer Museum in Boston. Serving as a benchmark throughout history, the Utah teapot has become an icon of 3D computer graphics. 25 11/27/2023  History of Computer Graphics 1975: At the age of 19, William (Bill) Gates III dropped out of Harvard and founds Microsoft with his friend Paul Allen. 1976 : The CRAY-I Super Computer is introduced and becomes the standard for large-scale scientific computing. 26 11/27/2023  History of Computer Graphics 1976: Steve Jobs and Steve Wozniak found Apple. After a visit of Xerox’s PARC in 1979, introducing the Macintosh in 1984 which will spark the graphical user interface revolution. 1977: Utah alumni Frank Crow develops solutions to the aliasing problem, i.e. anti-aliasing. 1977: The Academy of Motion Pictures Arts and Sciences introduces the category titled Visual Effects for the Oscars. The Best Animated Feature Film Award will then be approved in 2001. 27 11/27/2023  History of Computer Graphics 1977: Utah student James (Jim) Blinn (now at Microsoft Research) presents a new illumination model that considers surface facets, and a year later, introduces bump- mapping. 28 11/27/2023  History of Computer Graphics 1979: George Lucas hires Ed Catmull and many others from the NYIT, to form Lucasfilm’s CG team in San Rafael, CA. 29 11/27/2023  History of Computer Graphics 1980: Turner Whitted at Bell Labs (now at Microsoft Research) introduces a general ray tracing paradigm which incorporates reflection, refraction, antialiasing, and shadows. 30 11/27/2023  History of Computer Graphics 1980: The European Association for Computer Graphics is formed and the first EUROGRAPHICS conference held in Geneva. 1980: The MIT Media Lab is founded by Nicholas Negroponte. 1980: The computer animation production studios Pacific Data Images (PDI) is founded by Carl Rosendahl. 31 11/27/2023  History of Computer Graphics 1981: After some work on fractals while at Boeing in 1980, Loren Carpenter is hired by Lucasfilm and, in collaboration with Cook and Catmull, writes their first renderer, called REYES (Renders Everything You Ever Saw). It included the RenderMan Shading Language (Pat Hanrahan, now Stanford) and would eventually turn into the Renderman rendering engine. 32 11/27/2023  History of Computer Graphics 1981: IEEE Computer Society starts publishing a new journal, Computer Graphics and Applications. 1982: ACM starts publishing Transactions on Graphics TOG. 1982: Utah alumni James (Jim) Clark founds Silicon Graphics Inc. (SGI), a leader in producing low-end to high-end graphics workstations and supercomputers. 1982: After inventing the Postscript language, Utah alumni John Warnock founds Adobe Systems. 1982: Autodesk is founded and AutoCAD released. 33 11/27/2023  History of Computer Graphics 1982: Lucasfilm computer graphics division develops a one- minute shot for Star Trek II: The Wrath of Khan making the first use of fractal- generated landscape in a film. William (Bill) Reeves leads the Genesis Effect programming team and creates the so-called Particle Systems. 34 11/27/2023  History of Computer Graphics 1982: Disney releases Tron, the first film with 15 minutes of fully computer generated 3D shots including the famous Light Cycle sequence inside a videogame. The movie is now recognized as a landmark despite its box office failure. 35 11/27/2023  History of Computer Graphics 1984: The first movie to use “integrated CGI” where the effects are supposed to represent real world objects is released. The Last Starfighter includes CG spaceships, planets, and high-tech hardware integrated into live-action scenes, but will also be a box office failure. 36 11/27/2023  History of Computer Graphics 1984: Michael Cohen introduces the Cornell Box which will symbolize the approach to physically-based rendering. 1984: Based on heat transfer, Cindy Goral, Kenneth Torrance, Don Greenberg and Bennett Battaile at Cornell University introduce Radiosity, allowing realistic renderings. 37 11/27/2023  History of Computer Graphics 1984: Part of Lucasfilm’s team, Cornell alumni Robert (Rob) Cook proposes an extended version of ray-tracing. Distribution ray-tracing allows the realistic simulation of motion blur, depth of field, soft shadows, etc… 38 11/27/2023  History of Computer Graphics 1984: Lucasfilm’s computer animation division creates The Adventures of André and Wally B., the first all-CGI animated short film, followed by Pixar’s Luxo Jr. in 1985. 39 11/27/2023  History of Computer Graphics 1985: Ken Perlin introduces noise functions as a means of creating natural patterns such as marble, wood, … 40 11/27/2023  History of Computer Graphics 1986: Utah alumni James (Jim) Kajiya (now at Microsoft Research) introduces the Rendering Equation allowing realistic light inter- reflections to be path-traced. 41 11/27/2023  History of Computer Graphics 1986: The computer graphics division of Lucasfilm splits off as a separate company focused on animated films, Pixar, headed by Ed Catmull and purchased by Steve Jobs. 1986: Industrial Light and Magic (ILM), the special effects division of Lucasfilm, starts a CGI group. 1986: Mental Images is founded in Berlin, bought by Nvidia in 2007. 1989: REYES-based Pixar’s RenderMan system is released and a year later its shading language by Jim Lawson and Pat Hanrahan. 42 11/27/2023  History of Computer Graphics 1991: Although 3D computer graphics debuted in earlier in Disney productions, Beauty and the Beast is the first where hand-drawn characters appear with 3D animated objects. 43 11/27/2023  History of Computer Graphics 1992: Silicon Graphics Inc. (SGI) releases the Open Graphics Library (OpenGL) specification defining a standard cross-language cross-platform API for computer graphics (now managed by Khronos, being replaced by Vulkan). 1993: Nvidia is founded, later attracts many engineers from SGI and other companies to become the main graphics HW company (besides ATI and Intel today). 44 11/27/2023  History of Computer Graphics 1995: Pixar Animation Studios produce Toy Story, the first computer- animated full-length feature film, demonstrating the possibilities of CGI graphics in movie- making. 45 11/27/2023 History of Computer Graphics 1996: The 3D gaming industry sees a breakthrough with the release of Quake, lead by John Carmack at ID Software, which used actual 3-D models in a truly 3-D space. 46 11/27/2023  History of Computer Graphics 2001: Although it fails commercially, Final Fantasy - The Spirits Within is the first feature-length digital film that includes a cast of photorealistic digital actors, stirring the imagination of the press and CG community. Raises awareness of the “uncanny valley”. 47 11/27/2023 Applications of Computer Graphics  Computer Aided Design (CAD)  Graphics and Charts  Entertainment  Education & Training  Computer Art  Visualization  Image Processing  Graphical User Interfaces 48 11/27/2023  1. Computer Aided Design (CAD)  Used in design of buildings, automobiles, aircraft, watercraft, spacecraft, computers, textiles & many other products  AutoCAD software was the first CAD program.  Graphics design package provides standard shapes  Animations are also used in CAD applications  Realistic displays of architectural design. 49 11/27/2023 2. Graphs and Charts  Help for making reports  Summarize financial, statistical, mathematical, scientific, economic data for research reports, managerial reports  Presentation Slides  Bar charts, Line graphs, Pie charts etc. 50 11/27/2023 3. Entertainment I. Movie Industry Used in motion pictures, music, videos, and television shows. Used in making of cartoon animation films Computer Graphics is about animation (films). 51 11/27/2023 52 11/27/2023 Cont.. II. Game Industry Focus on interactivity Cost effective solutions Avoiding computations and other tricks 53 11/27/2023  4. Education & Training  Computer generated models of physical, financial and economic systems are used as educational aids.  Models of physical systems, physiological systems, population trends, or equipment such as color-coded diagram help trainees understand the operation of the system.  Specialized systems used for training applications Simulators for practice sessions or training of ship captains Aircraft pilots Heavy equipment operators Air traffic-control personnel 54 11/27/2023  Cont.. Computer Art Computer art typically refers to any form of graphic art or digital imagery which is produced with the aid of a computer. Used in Fine Art & Commercial Art Examples: Cartoon drawing, paintings, product advertisements, logo design 55 11/27/2023  Cont.. Visualization  Visualization is the process of representing data graphically and interacting with these representations in order to gain insight into the data.  Scientific Visualization Producing graphical representations for scientific, engineering, and medical data sets Scientists, engineers, medical personnel, business analysis, and others often need to analyze large amounts of information or to study the behavior of certain processes.  56 11/27/2023  Cont.. Image Processing  Image Processing applies techniques to modify or interpret existing pictures.  There are different examples of image processing in our daily life. It is used in: Image enhancement. Law Enforcement Medical Moving object tracking…etc.  Image enhancement  It is used to improve quality, remove noise from image. 57 11/27/2023  Cont.. Law Enforcement  Number Plate Recognition  Fingerprint Recognition 58 11/27/2023  Cont.. Medical  Different types of imaging tools such as X- ray, Ultrasound uses image processing to diagnose disease. 59 11/27/2023  Design Graphical User Interface  Computer graphics is used to design: Menus, icons, cursors, dialog boxes, scrollbars, valuators, grids, 3D interface.  Lay user can easily use the computer with the help of GUI.  User don’t have to remember commands.  More interactive interface. 60 11/27/2023  Graphics of hardware 61 11/27/2023  Display Devices 62 11/27/2023 Pixel What is Pixel?  Pixels are the basic building block of graphics display. We can call it picture element.  The pixel is a smallest size object or color spot that can be display and addressed on a screen. Any image that is display on the monitor is made up of thousands of pixels 63 11/27/2023 Dot What is Dot? The internal surface of the monitor screen is coated with Red, Green, Blue phosphor material.The glows when struck by the stream of electronics. The coated material is arranged into an array of millions of tiny cell. Red, Green Blue.These colored are usually called dots. 64 11/27/2023 Aspect ratio What is aspect Ratio? The aspect ratio of an image is the ratio of the number of x- pixels to number of y – pixels The standard aspect ratio is 4:3 or 5:4 Resolution: 1024X 768 Aspect ratio 1024:768=4:3 65 11/27/2023  Image Resolution  What is image Resolution? The distance from one pixel to next pixel is called the image resolution. The unit image resolution is ppi(pixel per inch) Typical display screen , image with resolution between 25ppi and 80ppi 66 11/27/2023 Screen resolution What is screen resolution? We can also call the screen resolution , the dot pitch The dot pitch is the distance between adjacent set(triads) of Red , Green Blue dots This is also some as the shortest distance between any two dots of the same color. i.e from Red-Red, Green-Green, Blue-Blue 67 11/27/2023  What is Video Display devices ? 68 11/27/2023 69 11/27/2023 70 11/27/2023 What is CRT? The cathode ray tube(CRT) is a vacuum tube containing an electronic gun and a fluorescent screen, with internal or external means to a accelerate and deflect the electronic beam used to create images in the form of light emitted from the fluorescent screen 71 11/27/2023 72 11/27/2023 73 11/27/2023 The operation of CRT is very simple: 1. The electron gun emits a beam of electrons (cathode rays). 2. The electron beam passes through focusing and deflection systems that direct it towards specified positions on the phosphor-coated screen. 3. When the beam hits the screen, the phosphor emits a small spot of light at each position contacted by the electron beam. 4. It redraws the picture by directing the electron beam back over the same screen points quickly. 74 11/27/2023 75 11/27/2023 76 11/27/2023 77 11/27/2023 78 11/27/2023 79 11/27/2023 80 11/27/2023 81 11/27/2023 82 11/27/2023  Raster Scan 83 11/27/2023 84 11/27/2023 85 11/27/2023 86 11/27/2023  Random Scan (Vector Scan) 87 11/27/2023 Random Scan :In this technique, the electron beam is directed only to the part of the screen where the picture is to be drawn rather than scanning from left to right and top to bottom as in raster scan. 88 11/27/2023 89 11/27/2023 90 11/27/2023 91 11/27/2023  Graphical Input Devices 92 11/27/2023 93 11/27/2023 94 11/27/2023 95 11/27/2023 96 11/27/2023 97 11/27/2023 98 11/27/2023 99 11/27/2023 100 11/27/2023 101 11/27/2023 102 11/27/2023 103 11/27/2023 104 11/27/2023 105 11/27/2023 106 11/27/2023 107 11/27/2023 108 11/27/2023 109 11/27/2023 110 11/27/2023 111 11/27/2023 112 11/27/2023 113 11/27/2023 114 11/27/2023 115 11/27/2023 116 11/27/2023 117 11/27/2023 118 11/27/2023 119 11/27/2023 120 11/27/2023 121 11/27/2023 122 11/27/2023 123 11/27/2023 124 11/27/2023 Quiz  The higher number of pixels gives us a ____ image - A. Better B. Worst C. Smaller D. None of the above  The components of Interactive computer graphics are - A. A monitor B. Display controller C. Frame buffer D. All of the above 125 11/27/2023  The End of 1st chapter 126 11/27/2023