Computer graphics

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A Blender 2.45 screenshot, displaying the 3D test model Suzanne.

Computer graphics are pictures and movies created using computers. Usually, the term refers to computer-generated image data created with help from specialized graphical hardware and software. It is a vast and recent area in computer science. The phrase was coined in 1960, by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, though sometimes erroneously referred to as CGI.

Important topics in computer graphics include user interface design, sprite graphics, vector graphics, 3D modeling, shaders, GPU design, implicit surface visualization with ray tracing, and computer vision, among others. The overall methodology depends heavily on the underlying sciences of geometry, optics, and physics.

Computer graphics is responsible for displaying art and image data effectively and meaningfully to the user. It is also used for processing image data received from the physical world. Computer graphic development has had a significant impact on many types of media and has revolutionized animation, movies, advertising, video games, and graphic design generally.


The term computer graphics has been used a broad sense to describe "almost everything on computers that is not text or sound".[1] Typically, 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

Today, computer graphics is widespread. Such imagery is found in and on television, newspapers, weather reports, and in a variety of medical investigations and surgical procedures. A well-constructed graph can present complex statistics in a form that is easier to understand and interpret. In the media "such graphs are used to illustrate papers, reports, thesis", and other presentation material.[2]




The precursor sciences to the development of modern computer graphics were the advances in electrical engineering, electronics, and television that took place during the first half of the twentieth century. Screens could display art since the Lumiere brothers' use of mattes to create special effects for the earliest films dating from 1895, but such displays were limited and not interactive. The first cathode ray tube, the Braun tube, was invented in 1897 - it in turn would permit the oscilloscope and the military control panel - the more direct precursors of the field, as they provided the first two-dimensional electronic displays that responded to programmatic or user input. Nevertheless, computer graphics remained relatively unknown as a discipline until the 1950s and the post-World War II period - during which time, the discipline emerged from a combination of both pure university and laboratory academic research into more advanced computers and the United States military's further development of technologies like radar, advanced aviation, and rocketry developed during the war. New kinds of displays were needed to process the wealth of information resulting from such projects, leading to the development of computer graphics as a discipline.


SAGE Sector Control Room.


Electronics pioneer Hewlett-Packard went public in 1957 after incorporating the decade prior, and established strong ties with Stanford University through its founders, who were alumni. This began the decades-long transformation of the southern San Francisco Bay Area into the world's leading computer technology hub - now known as Silicon Valley. The field of computer graphics developed with the emergence of computer graphics hardware.



The phrase “computer graphics” itself was coined in 1960 by William Fetter, a graphic designer for Boeing.[5] This old quote in many secondary sources comes complete with the following sentence: (Fetter has said that the terms were actually given to him by Verne Hudson of the Wichita Division of Boeing.)[6] In 1961 another student at MIT, Steve Russell, created the second video game, Spacewar. Written for the DEC PDP-1, Spacewar was an instant success and copies started flowing to other PDP-1 owners and eventually DEC got a copy.[citation needed] 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. (Higginbotham's Tennis For Two had beaten Spacewar by almost three years; but it was almost unknown outside of a research or academic setting.)

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.[7] 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 Sinden and Michael Noll started working in the computer graphics field. Sinden 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.

Also sometime in the early 1960s, automobiles would also provide a boost through the early work of Pierre Bézier at Renault, who used Paul de Casteljau's curves - now called Bézier curves after Bézier's work in the field - to develop 3d modeling techniques for Renault car bodies. These curves would form the foundation for much curve-modeling work in the field, as curves - unlike polygons - are mathematically complex entities to draw and model well.

Pong arcade version


Also in 1966, Ivan Sutherland continued to innovate at MIT when he 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 Director of Information Processing at ARPA (Advanced Research Projects Agency), and later became a professor at Harvard. In 1967 Sutherland was recruited by Evans to join the computer science program at the University of Utah - a development which would turn that department into one of the most important research centers in graphics for nearly a decade thereafter, eventually producing some of the most important pioneers in the field. There Sutherland perfected his HMD; twenty years later, NASA would re-discover his techniques in their virtual reality research. At Utah, Sutherland and Evans were highly sought after consultants by large companies, but they were frustrated at the lack of graphics hardware available at the time so they started formulating a plan to start their own company.

In 1968, Arthur Appel described the first algorithm for what would eventually become known as ray casting - a basis point for almost all of modern 3D graphics, as well as the later pursuit of photorealism in graphics.

In 1969, the ACM initiated A Special Interest Group on Graphics (SIGGRAPH) which organizes conferences, graphics standards, and publications within the field of computer graphics. By 1973, the first annual SIGGRAPH conference was held, which has become 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 the transformation of graphics from utilitarian to realistic occurred at the University of Utah in the 1970s, which had hired Ivan Sutherland away from MIT. Sutherland's graphics class would contribute a number of significant pioneers to the field, including a student by the name of Edwin Catmull - a later founder of Pixar. Because of David C. Evans' 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. 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.

As the UU computer graphics laboratory was attracting people from all over, John Warnock was one of those early pioneers; he would later found Adobe Systems and create a revolution in the publishing world with his PostScript page description language, and Adobe would go on later to create the industry standard photo editing software in Adobe Photoshop and the movie industry's special effects standard in Adobe After Effects. Tom Stockham led the image processing group at UU which worked closely with the computer graphics lab. Jim Clark was also there; he would later found Silicon Graphics. 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. The 3D Core Graphics System (or Core) was the first graphical standard to be developed. A group of 25 experts of the ACM Special Interest Group SIGGRAPH developed this "conceptual framework". The specifications were published in 1977, and it became a foundation for many future developments in the field.


The modern videogame arcade as is known today was birthed in the 1970s, with the first arcade games using real-time 2D sprite graphics. Pong in 1972 was one of the first hit arcade cabinet games. Speed Race in 1974 featured sprites moving along a vertically scrolling road. Gun Fight in 1975 featured human-looking sprite character graphics, while Space Invaders in 1978 featured a large number of sprites on screen; both used an Intel 8080 microprocessor and Fujitsu MB14241 video shifter to accelerate the drawing of sprite graphics.



The 1980s began to see the modernization and commercialization of computer graphics. As the home computer proliferated, a subject which had previously been an academics-only discipline was adopted by a much larger audience, and the number of computer graphics developers increased significantly.

In the early 1980s, the availability of bit-slice and 16-bit microprocessors started to revolutionize high-resolution computer graphics terminals which now increasingly became intelligent, semi-standalone and standalone workstations. Graphics and application processing were increasingly migrated to the intelligence in the workstation, rather than continuing to rely on central mainframe and mini-computers. Typical of the early move to high-resolution computer graphics intelligent workstations for the computer-aided engineering market were the Orca 1000, 2000 and 3000 workstations, developed by Orcatech of Ottawa, a spin-off from Bell-Northern Research, and led by David Pearson, an early workstation pioneer. The Orca 3000 was based on Motorola 68000 and AMD bit-slice processors and had Unix as its operating system. It was targeted squarely at the sophisticated end of the design engineering sector. Artists and graphic designers began to see the personal computer, particularly the Commodore Amiga and Macintosh, as a serious design tool, one that could save time and draw more accurately than other methods. The Macintosh remains a highly popular tool for computer graphics among graphic design studios and businesses. Modern computers, dating from the 1980s, often use 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.

In the field of realistic rendering, Japan's Osaka University developed the LINKS-1 Computer Graphics System, a supercomputer that used up to 257 Zilog Z8001 microprocessors, in 1982, for the purpose of rendering realistic 3D computer graphics. According to the Information Processing Society of Japan: "The core of 3D image rendering is calculating the luminance of each pixel making up a rendered surface from the given viewpoint, light source, and object position. The LINKS-1 system was developed to realize an image rendering methodology in which each pixel could be parallel processed independently using ray tracing. By developing a new software methodology specifically for high-speed image rendering, LINKS-1 was able to rapidly render highly realistic images. It was used to create the world's first 3D planetarium-like video of the entire heavens that was made completely with computer graphics. The video was presented at the Fujitsu pavilion at the 1985 International Exposition in Tsukuba."[8] The LINKS-1 was the world's most powerful computer, as of 1984.[9] Also in the field of realistic rendering, the general rendering equation of David Immel and James Kajiya was developed in 1986 - an important step towards implementing global illumination, which is necessary to pursue photorealism in computer graphics.

The continuing popularity of Star Wars and other science fiction franchises were relevant in cinematic CGI at this time, as Lucasfilm and Industrial Light & Magic became known as the "go-to" house by many other studios for topnotch computer graphics in film. Important advances in chroma keying ("bluescreening", etc.) were made for the later films of the original trilogy. Two other pieces of video would also outlast the era as historically relevant: Dire Straits' iconic, near-fully-CGI video for their song "Money For Nothing" in 1985, which popularized CGI among music fans of that era, and a scene from Young Sherlock Holmes the same year featuring the first fully CGI character in a feature movie (an animated stained-glass knight). In 1988, the first shaders - small programs designed specifically to do shading as a separate algorithm - were developed by Pixar, which had already spun off from Industrial Light & Magic as a separate entity - though the public would not see the results of such technological progress until the next decade. In the late 1980s, SGI computers were used to create some of the first fully computer-generated short films at Pixar, and Silicon Graphics machines were considered a high-water mark for the field during the decade.

The 1980s is also called the golden era of videogames; millions-selling systems from Atari, Nintendo and Sega, among other companies, exposed computer graphics for the first time to a new, young, and impressionable audience - as did MS-DOS-based personal computers, Apple IIs and Macs, and Amigas, which also allowed users to program their own games if skilled enough. Demoscenes and shareware games proliferated; John Carmack, a later 3D innovator, would start out in this period developing sprite-based games. In the arcades, advances were made in commercial, real-time 3D graphics. In 1988, the first dedicated real-time 3D graphics boards were introduced in arcades, with the Namco System 21[10] and Taito Air System.[11] This innovation would be the precursor of the later home graphics processing unit or GPU, a technology where a separate and very powerful chip is used in parallel processing with a CPU to optimize graphics.


Quarxs, series poster, Maurice Benayoun, François Schuiten, 1992

The 1990s' overwhelming note was the emergence of 3D modeling on a mass scale and an impressive rise in the quality of CGI generally. Home computers became able to take on rendering tasks that previously had been limited to workstations costing thousands of dollars; as 3D modelers became available for home systems, the popularity of Silicon Graphics workstations declined and powerful Microsoft Windows and Apple Macintosh machines running Autodesk products like 3D Studio or other home rendering software ascended in importance. By the end of the decade, the GPU would begin its rise to the prominence it still enjoys today.

The field began to see the first rendered graphics that could truly pass as photorealistic to the untrained eye (though they could not yet do so with a trained CGI artist) and 3D graphics became far more popular in gaming, multimedia, and animation. At the end of the 1980s and the beginning of the nineties were created, in France, the very first computer graphics TV series: La Vie des bêtes by studio Mac Guff Ligne (1988), Les Fables Géométriques (1989-1991) by studio Fantôme, and Quarxs, the first HDTV computer graphics series by Maurice Benayoun and François Schuiten (studio Z-A production, 1990–1993).

In film, Pixar began its serious commercial rise in this era under Edwin Catmull, with its first major film release, in 1995 - Toy Story - a critical and commercial success of nine-figure magnitude. The studio to invent the programmable shader would go on to have many animated hits, and its work on prerendered video animation is still considered an industry leader and research trail breaker.

In video games, in 1992, Virtua Racing, running on the Sega Model 1 arcade system board, laid the foundations for fully 3D racing games and popularized real-time 3D polygonal graphics among a wider audience in the video game industry.[12] The Sega Model 2 in 1993 and Sega Model 3 in 1996 subsequently pushed the boundaries of commercial, real-time 3D graphics. Back on the PC, Wolfenstein 3D, Doom and Quake, three of the first massively popular 3D first-person shooter games, were released by id Software to critical and popular acclaim during this decade using a rendering engine innovated primarily by John Carmack. The Sony Playstation and Nintendo 64, among other consoles, sold in the millions and popularized 3D graphics for home gamers. Certain late-90's first-generation 3D titles became seen as influential in popularizing 3D graphics among console users, such as platform games Super Mario 64 and The Legend Of Zelda: Ocarina Of Time, and early 3D fighting games like Virtua Fighter, Battle Arena Toshinden, and Tekken.

Technology and algorithms for rendering continued to improve greatly. In 1996, Krishnamurty and Levoy invented normal mapping - an improvement on Jim Blinn's bump mapping. 1999 saw Nvidia release the seminal GeForce 256, the first home video card billed as a graphics processing unit or GPU, which in its own words contained "integrated transform, lighting, triangle setup/clipping, and rendering engines". By the end of the decade, computers adopted common frameworks for graphics processing such as DirectX and OpenGL. Since then, computer graphics have only become more detailed and realistic, due to more powerful graphics hardware and 3D modeling software. AMD also became a leading developer of graphics boards in this decade, creating a "duopoly" in the field which exists this day.


CGI became ubiquitous in earnest during this era. Video games and CGI cinema had spread the reach of computer graphics to the mainstream by the late 1990s and continued to do so at an accelerated pace in the 2000s. CGI was also adopted en masse for television advertisements widely in the late 1990s and 2000s, and so became familiar to a massive audience.

The continued rise and increasing sophistication of the graphics processing unit were crucial to this decade, and 3D rendering capabilities became a standard feature as 3D-graphics GPUs became considered a necessity for desktop computer makers to offer. The Nvidia GeForce line of graphics cards dominated the market in the early decade with occasional significant competing presence from ATI.[13] As the decade progressed, even low-end machines usually contained a 3D-capable GPU of some kind as Nvidia and AMD both introduced low-priced chipsets and continued to dominate the market. Shaders which had been introduced in the 1980s to perform specialized processing on the GPU would by the end of the decade become supported on most consumer hardware, speeding up graphics considerably and allowing for greatly improved texture and shading in computer graphics via the widespread adoption of normal mapping, bump mapping, and a variety of other techniques allowing the simulation of a great amount of detail.

Computer graphics used in films and video games gradually began to be realistic to the point of entering the uncanny valley. CGI movies proliferated, with traditional animated cartoon films like Ice Age and Madagascar as well as numerous Pixar offerings like Finding Nemo dominating the box office in this field. The Final Fantasy: The Spirits Within, released in 2001, was the first fully computer-generated feature film to use photorealistic CGI characters and be fully made with motion capture.[14] The film was not a box-office success, however.[15] Some commentators have suggested this may be partly because the lead CGI characters had facial features which fell into the "uncanny valley".[16] Other animated films like The Polar Express drew attention at this time as well. Star Wars also resurfaced with its prequel trilogy and the effects continued to set a bar for CGI in film.

In videogames, the Sony PlayStation 2 and 3, the Microsoft Xbox line of consoles, and offerings from Nintendo such as the GameCube maintained a large following, as did the Windows PC. Marquee CGI-heavy titles like the series of Grand Theft Auto, Assassin's Creed, Final Fantasy, Bioshock, Kingdom Hearts, Mirror's Edge and dozens of others continued to approach photorealism, grow the video game industry and impress, until that industry's revenues became comparable to those of movies. Microsoft made a decision to expose DirectX more easily to the independent developer world with the XNA program, but it was not a success. DirectX itself remained a commercial success, however. OpenGL continued to mature as well, and it and DirectX improved greatly; the second-generation shader languages HLSL and GLSL began to be popular in this decade.

In scientific computing, the GPGPU technique to pass large amounts of data bidirectionally between a GPU and CPU was invented; speeding up analysis on many kinds of bioinformatics and molecular biology experiments. The technique has also been used for Bitcoin mining and has applications in computer vision.


Box art from Titanfall, 2014

In the early half of the 2010s, CGI is nearly ubiquitous in video, pre-rendered graphics are nearly scientifically photorealistic, and real-time graphics on a suitably high-end system may simulate photorealism to the untrained eye.

Texture mapping has matured into a multistage process with many layers; generally, it is not uncommon to implement texture mapping, bump mapping or isosurfaces, normal mapping, lighting maps including specular highlights and reflection techniques, and shadow volumes into one rendering engine using shaders, which are maturing considerably. Shaders are now very nearly a necessity for advanced work in the field, providing considerable complexity in manipulating pixels, vertices, and textures on a per-element basis, and countless possible effects. Their shader languages HLSL and GLSL are active fields of research and development. Physically based rendering or PBR, which implements even more maps to simulate real optic light flow, is an active research area as well, along with advanced optics areas like subsurface scattering and photon mapping. Experiments into the processing power required to provide graphics in real time at ultra-high-resolution modes like Ultra HD are beginning, though beyond reach of all but the highest-end hardware.

In cinema, most animated movies are CGI now; a great many animated CGI films are made per year, but few, if any, attempt photorealism due to continuing fears of the uncanny valley. Most are 3D cartoons.

In videogames, the Xbox One by Microsoft, Sony Playstation 4, and Nintendo Wii U currently dominate the home space and are all capable of highly advanced 3D graphics; the Windows PC is still one of the most active gaming platforms as well.

Image types[edit]


Main article: 2D computer graphics
Raster graphic sprites (left) and masks (right)



Pixel art[edit]

See also: Pixel art


Sprite graphics[edit]



Vector graphics[edit]

See also: Vector graphics



Main article: 3D computer graphics

3D graphics, compared to 2D graphics, are graphics that use a three-dimensional representation of geometric data. For the purpose of performance, this is stored in the computer. This includes images that may be for later display or for real-time viewing.



Computer animation[edit]

Example of Computer animation produced using Motion capture




Concepts and principles[edit]

Images are typically created by devices such as cameras, mirrors, lenses, telescopes, microscopes, etc.








Primitives are basic units which a graphics system may combine to create more complex images or models. Examples would be sprites and character maps in 2d video games, geometric primitives in CAD, or polygons or triangles in 3d rendering. Primitives may be supported in hardware for efficient rendering, or the building blocks provided by a graphics application



3D projection
Ray tracing
Example of shading.
Texture mapping
Texture mapping is a method for adding detail, surface texture, or colour to a computer-generated graphic or 3D model. Its application to 3D graphics was pioneered by Dr Edwin Catmull in 1974. A texture map is applied (mapped) to the surface of a shape, or polygon. This process is akin to applying patterned paper to a plain white box. Multitexturing is the use of more than one texture at a time on a polygon.[19] Procedural textures (created from adjusting parameters of an underlying algorithm that produces an output texture), and bitmap textures (created in an image editing application or imported from a digital camera) are, generally speaking, common methods of implementing texture definition on 3D models in computer graphics software, while intended placement of textures onto a model's surface often requires a technique known as UV mapping (arbitrary, manual layout of texture coordinates) for polygon surfaces, while NURBS surfaces have their own intrinsic parameterization used as texture coordinates. Texture mapping as a discipline also encompasses techniques for creating normal maps and bump maps that correspond to a texture to simulate height and specular maps to help simulate shine and light reflections, as well as environment mapping to simulate mirror-like reflectivity, also called gloss.

Volume rendering[edit]




3D modeling[edit]

Main article: 3D modeling


Pioneers in computer graphics[edit]

Charles Csuri
Donald P. Greenberg
A. Michael Noll
Noll was one of the first researchers to use a digital computer to create artistic patterns and to formalize the use of random processes in the creation of visual arts. He began creating digital computer art in 1962, making him one of the earliest digital computer artists. In 1965, Noll along with Frieder Nake and Georg Nees were the first to publicly exhibit their computer art. During April 1965, the Howard Wise Gallery exhibited Noll's computer art along with random-dot patterns by Bela Julesz.

Other pioneers[edit]


Important organizations[edit]

Study of computer graphics[edit]




Computer graphics may be used in the following areas:

See also[edit]


  5. ^ a b Wayne Carlson (2003) A Critical History of Computer Graphics and Animation Archived April 5, 2007, at the Wayback Machine.. Ohio State University
  6. ^ Jon Peddie: The History of Visual Magic in Computers: How Beautiful Images are Made in CAD, 3D, VR and AR, Springer, 2013, p. 101, ISBN 978-1447149316
  8. ^ Information Processing Society of Japan. "LINKS-1 Computer Graphics System-Computer Museum". Retrieved 15 June 2015. 
  9. ^
  10. ^ "System 16 - Namco System 21 Hardware (Namco)". Retrieved 15 June 2015. 
  11. ^ "System 16 - Taito Air System Hardware (Taito)". Retrieved 15 June 2015. 
  12. ^ "Virtua Racing – Arcade (1992)". 15 Most Influential Games of All Time. GameSpot. 14 March 2001. Archived from the original on 2010-04-12. Retrieved 19 January 2014. 
  13. ^ The Future Of Computer Graphics Daniel Sevo, 2005 (retrieved 26 February 2015)
  16. ^ The uncanny valley is a hypothesis in the field of robotics and 3D computer animation, which holds that when human replicas look and act almost, but not perfectly, like actual human beings, it causes a response of revulsion among human observers. The concept "valley" refers to the dip in a graph of the comfort level of humans as a function of a robot's human likeness.
  17. ^ Greenberg, Ira (2007). Processing: Creative Coding and Computational Art. Apress. ISBN 1-59059-617-X. 

Further reading[edit]


External links[edit]