Introduction to Computer Graphics

Computer graphics is a sub-field of computer science which studies methods for digitally synthesizing and manipulating visual content. Although the term often refers to the study of three-dimensional computer graphics, it also encompasses two-dimensional graphics and image processing [2].

Computer graphics may be used in the following areas [3]:

· Computational biology involves the development and application of data-analytical and theoretical methods, mathematical modeling and computational simulation techniques to the study of biological, behavioral, and social systems.

· Computational physics is the study and implementation of numerical algorithms to solve problems in physics for which the quantitative theory already exists.

· Computer-aided design (CAD), also known as computer-aided design and drafting (CADD), is the use of computer technology for the process of design.

· A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system.

· Digital art is a general term for a range of artistic works and practices that use digital technology as an essential part of the creative and/or presentation process.

· Education in the general sense is any act or experience that has a formative effect on the mind, character, or physical ability of an individual.

· Graphic design is a creative process – most often involving a client and a designer and usually completed in conjunction with producers of form (i.e., printers, programmers, sign makers, etc.) – undertaken in order to convey a specific message (or messages) to a targeted audience.

· Information graphics are graphic visual representations of information, data or knowledge.

· Information visualization is the interdisciplinary study of the visual representation of large-scale collections of non-numerical information, such as files and lines of code in software systems, library and bibliographic databases, networks of relations on the Internet, and so forth.

· Drug design, also sometimes referred to as rational drug design or structure based drug design, is the inventive process of finding new medications based on the knowledge of the biological target.

· Scientific visualization is an interdisciplinary branch of science primarily concerned with the visualization of three-dimensional phenomena (architectural, meteorological, medical, biological, etc.), where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps with a dynamic (time) component.

· A video game is an electronic game that involves interaction with a user interface to generate visual feedback on a video device.

· Virtual reality (VR) is a term that applies to computer-simulated environments that can simulate physical presence in places in the real world, as well as in imaginary worlds.

· Web design is the process of planning and creating a website.

Some information about Computer Graphics history [3].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 (Cathode Ray Tube) as a viable display and interaction interface and introduced the light pen as an input device.

Further advances in computing led to greater advancements in interactive computer graphics. In 1959, the TX-2 computer was developed at Lincoln Laboratory at Massachusetts Institute of Technology (MIT). The TX-2 integrated a number of new man-machine interfaces. A light pen could be used to draw sketches on the computer using Ivan Sutherland's revolutionary Sketchpad software. Using a light pen, Sketchpad allowed anyone to draw simple shapes on the computer screen, save them and even recall them later. The light pen itself had a small photoelectric cell in its tip. This cell emitted an electronic pulse whenever it was placed in front of a computer screen and the screen electron gun fired directly at it. By simply timing the electronic pulse with the current location of the electron gun, it was easy to pinpoint exactly where the pen was on the screen at any given moment. Once that was determined, the computer could then draw a cursor at that location.

Sutherland seemed to find the perfect solution for many of the graphics problems he faced. Even today, many standards of computer graphics interfaces got their start with this early Sketchpad program. One example of this is in drawing constraints. If one wants to draw a square for example, he does not have to worry about drawing four lines perfectly to form the edges of the box. One can simply specify that he wants to draw a box, and then specify the location and size of the box. The software will then construct a perfect box, with the right dimensions and at the right location. Another example is that Sutherland's software modeled objects – not just a picture of objects. In other words, with a model of a car, one could change the size of the tires without affecting the rest of the car. It could stretch the body of the car without deforming the tires.

These early computer graphics were vector graphics, composed of thin lines whereas modern day graphics are raster based using pixels.

Also in 1961 another student at MIT, Steve Russell, created the first video game, Spacewar. Written for the Digital Equipment Corporation PDP-1, Spacewar was an instant success and copies started flowing to other PDP-1 owners and eventually even DEC got a copy. The engineers at DEC used it as a diagnostic program on every new PDP-1 before shipping it. The sales force picked up on this quickly enough and when installing new units, would run the world's first video game for their new customers.

E. E. Zajac, a scientist at Bell Telephone Laboratory (BTL), created a film called "Simulation of a two-giro gravity attitude control system" in 1963. In this computer generated film, Zajac showed how the attitude of a satellite could be altered as it orbits the Earth. He created the animation on an IBM 7090 mainframe computer. Also at BTL, Ken Knowlton, Frank Sindon and Michael Noll started working in the computer graphics field. Sindon created a film called “Force, Mass and Motion” illustrating Newton's laws of motion in operation. Around the same time, other scientists were creating computer graphics to illustrate their research. At Lawrence Radiation Laboratory, Nelson Max created the films, "Flow of a Viscous Fluid" and "Propagation of Shock Waves in a Solid Form." Boeing Aircraft created a film called "Vibration of an Aircraft."

It was not long before major corporations started taking an interest in computer graphics. TRW, Lockheed-Georgia, General Electric and Sperry Rand are among the many companies that were getting started in computer graphics by the mid-1960s. IBM was quick to respond to this interest by releasing the IBM 2250 graphics terminal, the first commercially available graphics computer.

Ralph Baer, a supervising engineer at Sanders Associates, came up with a home video game in 1966 that was later licensed to Magnavox and called the “Odyssey”. While very simplistic, and requiring fairly inexpensive electronic parts, it allowed the player to move points of light around on a screen. It was the first consumer computer graphics product.

Also in 1966, Sutherland at MIT invented the first computer controlled head-mounted display (HMD). Called the Sword of Damocles because of the hardware required for support, it displayed two separate wireframe images, one for each eye. This allowed the viewer to see the computer scene in stereoscopic 3D. After receiving his Ph.D. from MIT, Sutherland became a Director of Information Processing at ARPA (Advanced Research Projects Agency), and later became a professor at Harvard.

David C. Evans was a director of engineering at Bendix Corporation's computer division from 1953 to 1962, after he worked for the next five years as a visiting professor at Berkeley. There he continued to show interest in computers and how they interfaced with people. In 1968 the University of Utah recruited Evans to start a computer science program, and computer graphics quickly became his primary interest. This new department became shortly the world's primary research center for computer graphics.

In 1967 Sutherland was recruited by Evans to join the computer science program at the University of Utah (UU). There he perfected his HMD. Twenty years later, NASA (National Aeronautics and Space Administration) rediscovered his techniques in their virtual reality research. At Utah, Sutherland and Evans were highly sought after consultants by large companies but they were frustrated with the lack of graphics hardware available at the time so they started formulating a plan to start their own company.

In 1969, the ACM initiated A Special Interest Group in Graphics (SIGGRAPH) which organized conferences, graphics standards, and publications within the field of computer graphics. In 1973, the first annual SIGGRAPH conference was held, which became one of the focuses of the organization. SIGGRAPH has grown in size and importance as the field of computer graphics has expanded over time.

Many of the most important early breakthroughs in computer graphics research occurred at the UU in the 1970s. A student by the name of Edwin Catmull signed up for Sutherland's computer graphics class. Catmull had just come from The Boeing Company and had been working on his degree in physics. Growing up on Disney, Catmull loved animation yet quickly discovered that he did not have the talent for drawing. Now Catmull (along with many others) saw computers as the natural progression of animation and they wanted to be part of the revolution. The first animation that Catmull saw was his own. He created an animation of his hand opening and closing. It became one of his goals to produce a feature length motion picture using computer graphics. In the same class, Fred Parke created an animation of his wife's face. Because of Evan's and Sutherland's presence, UU was gaining quite a reputation as the place to be for computer graphics research so Catmull went there to learn 3D animation.

As the UU computer graphics laboratory was attracting people from all over, John Warnock was one of those early pioneers; he later found Adobe Systems and created a revolution in the publishing world with his PostScript page description language. Tom Stockham led the image processing group at UU which worked closely with the computer graphics lab. Jim Clark was also there; he later founded Silicon Graphics, Inc.

The first major advance in 3D computer graphics was created at UU by these early pioneers, the hidden-surface algorithm. In order to draw a representation of a 3D object on the screen, the computer must determine which surfaces are "behind" the object from the viewer's perspective, and thus should be "hidden" when the computer creates (or renders) the image.

In the 1980s, artists and graphic designers began to see the personal computer, particularly the Commodore Amiga and Macintosh, as a serious design tool, that could save time and draw more accurately than other methods. In the late 1980s, SGI (Common Gateway Interface) computers were used to create some of the first fully computer-generated short films at Pixar. The Macintosh remains a highly popular tool for computer graphics among graphic design studios and businesses. Since 1980s modern computers have often used graphical user interfaces (GUI) to present data and information with symbols, icons and pictures, rather than text. Graphics are one of the five key elements of multimedia technology.

3D graphics became more popular in the 1990s in gaming, multimedia and animation. At the end of the 80s and beginning of the 90s were created, in France, the very first computer graphics TV series: "La Vie des bêtes" by studio Mac Guff Ligne (1988), “Les Fables Géométriques” by J.-Y. Grall, Georges Lacroix and Renato (studio Fantome, 1990-1993) and “Quarxs”, the first HDTV computer graphics series by Maurice Benayoun and François Schuiten (studio Z-A production, 1991-1993). In 1995, “Toy Story”, the first full-length computer-generated animation film, was released in cinemas worldwide. In 1996, “Quake”, one of the first fully 3D games, was released. Since then, computer graphics have only become more detailed and realistic, due to more powerful graphics hardware and 3D modeling software.

Поиск по сайту: