Computer graphics deals with generatingimages and art with the aid ofcomputers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven bycomputer graphics hardware. It is a vast and recently developed area of computer science. The phrase was coined in 1960 by computer graphics researchers Verne Hudson andWilliam Fetter of Boeing. It is often abbreviated as CG, or typically in the context of film ascomputer generated imagery (CGI). The non-artistic aspects of computer graphics are the subject ofcomputer science research.[1]
Computer graphics is responsible for displaying art and image data effectively and meaningfully to the consumer. It is also used for processing image data received from the physical world, such as photo and video content. Computer graphics development has had a significant impact on many types of media and has revolutionizedanimation,movies,advertising, andvideo games, in general.
The term computer graphics has been used in a broad sense to describe "almost everything on computers that is not text or sound".[2] Typically, the termcomputer graphics refers to several different things:
the representation and manipulation of image data by a computer
the varioustechnologies 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-constructedgraph 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, theses", and other presentation material.[3]
Many tools have been developed to visualize data. Computer-generated imagery can be categorized into several different types: two dimensional (2D), three dimensional (3D), and animated graphics. As technology has improved,3D computer graphics have become more common, but2D computer graphics are still widely used. Computer graphics has emerged as a sub-field ofcomputer science which studies methods for digitally synthesizing and manipulating visual content. Over the past decade, other specialized fields have been developed likeinformation visualization, andscientific visualization more concerned with "the visualization ofthree 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".[4]
The precursor sciences to the development of modern computer graphics were the advances inelectrical engineering,electronics, andtelevision that took place during the first half of the twentieth century. Screens could display art since theLumiere brothers' use ofmattes to create special effects for the earliest films dating from 1895, but such displays were limited and not interactive. The firstcathode ray tube, theBraun tube, was invented in 1897 – it in turn would permit theoscilloscope and the militarycontrol 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 pureuniversity andlaboratory academic research into more advanced computers and theUnited States military's further development of technologies likeradar,aviation, androcketry 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.[5]
Early projects like theWhirlwind andSAGE Projects introduced theCRT as a viabledisplay and interaction interface and introduced thelight pen as aninput device.Douglas T. Ross of the Whirlwind SAGE system performed a personal experiment in which he wrote a small program that captured the movement of his finger and displayed its vector (his traced name) on a display scope. One of the first interactive video games to feature recognizable, interactive graphics –Tennis for Two – was created for an oscilloscope byWilliam Higinbotham to entertain visitors in 1958 atBrookhaven National Laboratory and simulated a tennis match. In 1959,Douglas T. Ross, while working at MIT on transforming mathematic statements into computer generated 3D machine tool vectors, created a display scope image of aDisneycartoon character.[6]
Electronics pioneerHewlett-Packard went public in 1957 after incorporating the decade prior, and established strong ties withStanford University through its founders, who werealumni. This began the decades-long transformation of the southernSan Francisco Bay Area into the world's leading computer technology hub – now known asSilicon Valley. The field of computer graphics developed with the emergence of computer graphics hardware.
Further advances in computing led to greater advancements ininteractive computer graphics. In 1959, theTX-2 computer was developed atMIT's Lincoln Laboratory. The TX-2 integrated a number of new man-machine interfaces. Alight pen could be used to draw sketches on the computer usingIvan Sutherland's revolutionarySketchpad software.[7] Using a light pen, Sketchpad allowed one to draw simple shapes on the computer screen, save them and even recall them later. The light pen itself had a smallphotoelectric cell in its tip. This cell emitted an electronic pulse whenever it was placed in front of a computer screen and the screen'selectron 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, they do not have to worry about drawing four lines perfectly to form the edges of the box. One can simply specify that they want 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 car without deforming the tires.
The phrase "computer graphics" has been credited toWilliam Fetter, a graphic designer forBoeing in 1960. Fetter in turn attributed it to Verne Hudson, also at Boeing.[7][8]
In 1961 another student at MIT,Steve Russell, created another important title in the history ofvideo games,Spacewar! Written for theDEC PDP-1,Spacewar was an instant success and copies started flowing to otherPDP-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'sTennis For Two had beatenSpacewar by almost three years, but it was almost unknown outside of a research or academic setting.)
At around the same time (1961–1962) in the University of Cambridge, Elizabeth Waldram wrote code to display radio-astronomy maps on a cathode ray tube.[9]
E. E. Zajac, a scientist atBell Telephone Laboratory (BTL), created a film called "Simulation of a two-giro gravity attitude control system" in 1963.[10] 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 anIBM 7090 mainframe computer. Also at BTL,Ken Knowlton, Frank Sinden,Ruth A. Weiss andMichael Noll started working in the computer graphics field. Sinden created a film calledForce, Mass and Motion illustratingNewton's laws of motion in operation. Around the same time, other scientists were creating computer graphics to illustrate their research. AtLawrence Radiation Laboratory, Nelson Max created the filmsFlow of a Viscous Fluid andPropagation of Shock Waves in a Solid Form.Boeing Aircraft created a film calledVibration of an Aircraft.
Also sometime in the early 1960s,automobiles would also provide a boost through the early work ofPierre Bézier atRenault, who usedPaul de Casteljau's curves – now calledBézier curves after Bézier's work in the field – to develop 3d modeling techniques forRenault 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.
It was not long before major corporations started taking an interest in computer graphics.TRW,Lockheed-Georgia,General Electric andSperry 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 theIBM 2250 graphics terminal, the first commercially available graphics computer.Ralph Baer, a supervising engineer atSanders Associates, came up with a homevideo game in 1966 that was later licensed toMagnavox and called theOdyssey. 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.David C. Evans was director of engineering atBendix Corporation's computer division from 1953 to 1962, after which he worked for the next five years as a visiting professor at Berkeley. There he continued his interest in computers and how they interfaced with people. In 1966, theUniversity of Utah recruited Evans to form a computer science program, and computer graphics quickly became his primary interest. This new department would become the world's primary research center for computer graphics through the 1970s.
Also, in 1966,Ivan Sutherland continued to innovate at MIT when he invented the first computer-controlledhead-mounted display (HMD). It displayed two separate wireframe images, one for each eye. This allowed the viewer to see the computer scene instereoscopic 3D. The heavy hardware required for supporting the display and tracker was called the Sword of Damocles because of the potential danger if it were to fall upon the wearer. After receiving his Ph.D. from MIT, Sutherland became Director of Information Processing atARPA (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 theUniversity 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 theirvirtual 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.
A 1968 center spread from Seattle underground paperHelix features then-state-of-the-art computer graphics.
In 1968, Dave Evans and Ivan Sutherland founded the first computer graphics hardware company,Evans & Sutherland. While Sutherland originally wanted the company to be located in Cambridge, Massachusetts, Salt Lake City was instead chosen due to its proximity to the professors' research group at the University of Utah.
Also in 1968 Arthur Appel described the firstray casting algorithm, the first of a class ofray tracing-based rendering algorithms that have since become fundamental in achievingphotorealism in graphics by modeling the paths that rays of light take from a light source, to surfaces in a scene, and into the camera.
In 1969, theACM initiated A Special Interest Group on Graphics (SIGGRAPH) which organizesconferences,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.
TheUtah teapot byMartin Newell and its static renders became emblematic of CGI development during the 1970s.
Subsequently, a number of breakthroughs in the field occurred at theUniversity of Utah in the 1970s, which had hiredIvan Sutherland. He was paired withDavid C. Evans to teach an advanced computer graphics class, which contributed a great deal of founding research to the field and taught several students who would grow to found several of the industry's most important companies – namelyPixar,Silicon Graphics, andAdobe Systems. Tom Stockham led the image processing group at UU which worked closely with the computer graphics lab.
One of these students wasEdwin Catmull. Catmull had just come fromThe Boeing Company and had been working on his degree in physics. Growing up onDisney, 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 computer animation that Catmull saw was his own. He created an animation of his hand opening and closing. He also pioneeredtexture mapping to painttextures on three-dimensional models in 1974, now considered one of the fundamental techniques in3D modeling. It became one of his goals to produce a feature-length motion picture using computer graphics – a goal he would achieve two decades later after his founding role inPixar. In the same class,Fred Parke created an animation of his wife's face. The two animations were included in the 1976 feature filmFutureworld.
As the UU computer graphics laboratory was attracting people from all over,John Warnock was another of those early pioneers; he later foundedAdobe Systems and created a revolution in the publishing world with hisPostScript page description language. Adobe would go on later to create the industry standardphoto editing software inAdobe Photoshop and a prominent movie industryspecial effects program inAdobe After Effects.
James Clark was also there; he later foundedSilicon Graphics, a maker of advanced rendering systems that would dominate the field of high-end graphics until the early 1990s.
A major advance in 3D computer graphics was created at UU by these early pioneers –hidden surface determination. 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. The3D Core Graphics System (orCore) was the first graphical standard to be developed. A group of 25 experts of theACMSpecial Interest GroupSIGGRAPH developed this "conceptual framework". The specifications were published in 1977, and it became a foundation for many future developments in the field.
Also in the 1970s,Henri Gouraud,Jim Blinn andBui Tuong Phong contributed to the foundations ofshading in CGI via the development of theGouraud shading andBlinn–Phong shading models, allowing graphics to move beyond a "flat" look to a look more accurately portraying depth.Jim Blinn also innovated further in 1978 by introducingbump mapping, a technique for simulating uneven surfaces, and the predecessor to many more advanced kinds of mapping used today.
The modernvideogame arcade as is known today was birthed in the 1970s, with the firstarcade games usingreal-time2D sprite graphics.Pong in 1972 was one of the first hit arcade cabinet games.Speed Race in 1974 featuredsprites moving along a verticallyscrolling road.Gun Fight in 1975 featured human-looking animated characters, whileSpace Invaders in 1978 featured a large number of animated figures on screen; both used a specializedbarrel shifter circuit made from discrete chips to help theirIntel 8080microprocessor animate theirframebuffer graphics.
Donkey Kong was one of thevideo games that helped to popularize computer graphics to a mass audience in the 1980s.
The 1980s began to see the commercialization of computer graphics. As thehome 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.
Computer graphics terminals during this decade became increasingly 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 andminicomputers. 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 fromBell-Northern Research, and led by David Pearson, an early workstation pioneer. The Orca 3000 was based on the 16-bitMotorola 68000 microprocessor andAMDbit-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 theAmiga andMacintosh, 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 usegraphical user interfaces (GUI) to present data and information with symbols, icons and pictures, rather than text. Graphics are one of the five key elements ofmultimedia technology.
In the field of realistic rendering,Japan'sOsaka University developed theLINKS-1 Computer Graphics System, asupercomputer that used up to 257Zilog Z8001microprocessors, in 1982, for the purpose of rendering realistic3D 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 usingray tracing. By developing a new software methodology specifically for high-speed image rendering, LINKS-1 was able to rapidly render highly realistic images."[15] The LINKS-1 was the world's most powerfulcomputer, as of 1984.[16]
Also in the field of realistic rendering, the generalrendering equation of David Immel andJames Kajiya was developed in 1986 – an important step towards implementingglobal illumination, which is necessary to pursuephotorealism in computer graphics.
The continuing popularity ofStar Wars and other science fiction franchises were relevant in cinematic CGI at this time, asLucasfilm andIndustrial Light & Magic became known as the "go-to" house by many other studios for topnotch computer graphics in film. Important advances inchroma 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 fromYoung Sherlock Holmes the same year featuring the first fully CGI character in a feature movie (an animated stained-glassknight). In 1988, the firstshaders – small programs designed specifically to doshading as a separate algorithm – were developed byPixar, 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,Silicon Graphics (SGI) computers were used to create some of the first fully computer-generatedshort films atPixar, and Silicon Graphics machines were considered a high-water mark for the field during the decade.
The 1980s is also called thegolden era ofvideogames; millions-selling systems fromAtari,Nintendo andSega, among other companies, exposed computer graphics for the first time to a new, young, and impressionable audience – as didMS-DOS-based personal computers,Apple IIs,Macs, andAmigas, all of which also allowed users to program their own games if skilled enough. For thearcades, advances were made in commercial,real-time 3D graphics. In 1988, the first dedicated real-time 3Dgraphics boards were introduced for arcades, with theNamco System 21[17] andTaito Air System.[18] On the professional side,Evans & Sutherland and SGI developed 3D raster graphics hardware that directly influenced the later single-chipgraphics processing unit (GPU), a technology where a separate and very powerful chip is used inparallel processing with aCPU to optimize graphics.
The decade also saw computer graphics applied to many additional professional markets, including location-based entertainment and education with the E&S Digistar, vehicle design, vehicle simulation, and chemistry.
The 1990s' highlight was the emergence of3D modeling on a mass scale and an 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; as3D modelers became available for home systems, the popularity ofSilicon Graphics workstations declined and powerfulMicrosoft Windows andApple Macintosh machines runningAutodesk products like3D Studio or other home rendering software ascended in importance. By the end of the decade, theGPU would begin its rise to the prominence it still enjoys today.
The field began to see the first rendered graphics that could truly pass asphotorealistic to the untrained eye (though they could not yet do so with a trained CGI artist) and3D graphics became far more popular ingaming,multimedia, andanimation. 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, andQuarxs, the first HDTV computer graphics series byMaurice Benayoun andFrançois Schuiten (studio Z-A production, 1990–1993).
In film,Pixar began its serious commercial rise in this era underEdwin 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 programmableshader 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.
Technology and algorithms for rendering continued to improve greatly. In 1996, Krishnamurty and Levoy inventednormal mapping – an improvement on Jim Blinn'sbump mapping. 1999 sawNvidia release the seminalGeForce 256, the first homevideo card billed as agraphics processing unit or GPU, which in its own words contained "integratedtransform,lighting,triangle setup/clipping, andrendering engines". By the end of the decade, computers adopted common frameworks for graphics processing such asDirectX andOpenGL. Since then, computer graphics have only become more detailed and realistic, due to more powerfulgraphics hardware and3D 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 CGIcinema 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 adopteden masse fortelevision advertisements widely in the late 1990s and 2000s, and so became familiar to a massive audience.
The continued rise and increasing sophistication of thegraphics processing unit were crucial to this decade, and 3D rendering capabilities became a standard feature as 3D-graphics GPUs became considered a necessity fordesktop computer makers to offer. TheNvidia GeForce line of graphics cards dominated the market in the early decade with occasional significant competing presence fromATI.[20] As the decade progressed, even low-end machines usually contained a 3D-capable GPU of some kind asNvidia andAMD 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 improvedtexture andshading in computer graphics via the widespread adoption ofnormal mapping,bump mapping, and a variety of other techniques allowing the simulation of a great amount of detail.
Computer graphics used in films andvideo games gradually began to be realistic to the point of entering theuncanny valley.CGI movies proliferated, with traditional animatedcartoon films likeIce Age andMadagascar as well as numerousPixar offerings likeFinding Nemo dominating the box office in this field. TheFinal 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.[21] The film was not a box-office success, however.[22] Some commentators have suggested this may be partly because the lead CGI characters had facial features which fell into the "uncanny valley".[note 1] Other animated films likeThe 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.
Invideogames, the SonyPlayStation 2 and3, the MicrosoftXbox line of consoles, and offerings fromNintendo such as theGameCube maintained a large following, as did theWindows PC. Marquee CGI-heavy titles like the series ofGrand Theft Auto,Assassin's Creed,Final Fantasy,BioShock,Kingdom Hearts,Mirror's Edge and dozens of others continued to approachphotorealism, grow the video game industry and impress, until that industry's revenues became comparable to those of movies.Microsoft made a decision to exposeDirectX more easily to the independent developer world with theXNA program, but it was not a success. DirectX itself remained a commercial success, however.OpenGL continued to mature as well, and it andDirectX improved greatly; the second-generation shader languagesHLSL andGLSL began to be popular in this decade.
Adiamond plate texture rendered close-up usingphysically based rendering principles – increasingly an active area of research for computer graphics in the 2010s
In the 2010s, CGI has been nearly ubiquitous in video, pre-rendered graphics are nearly scientificallyphotorealistic, 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 orisosurfaces ornormal mapping, lighting maps includingspecular highlights andreflection techniques, andshadow volumes into one rendering engine usingshaders, which are maturing considerably. Shaders are now very nearly a necessity for advanced work in the field, providing considerable complexity in manipulatingpixels,vertices, and textures on a per-element basis, and countless possible effects. Their shader languagesHLSL andGLSL are active fields of research and development.Physically based rendering or PBR, which implements many maps and performs advanced calculation to simulate realoptic light flow, is an active research area as well, along with advanced areas likeambient occlusion,subsurface scattering,Rayleigh scattering,photon mapping,ray-tracing and many others. Experiments into the processing power required to provide graphics inreal time at ultra-high-resolution modes like4K Ultra HD begun, though beyond reach of all but the highest-end hardware.
In videogames, the MicrosoftXbox One, SonyPlayStation 4, andNintendo Switch dominated the home space and were all capable of advanced 3D graphics;Windows was still one of the most active gaming platforms as well.
This sectionneeds expansion. You can help byadding to it.(October 2024)
In the 2020s', advances in ray-tracing technology allowed it to be used for real-time rendering, as well as AI-powered graphics for generating or upscaling
While ray-tracing existed before,Nvidia was the first to push for ray-tracing with ray-tracing cores, as well as for AI withDLSS and Tensor cores. AMD followed suit with the same; FSR, Tensor cores and ray-tracing cores.
2D computer graphics are the computer-based generation ofdigital images—mostly from models, such as digital image, and by techniques specific to them.
2D computer graphics are mainly used in applications that were originally developed upon traditionalprinting anddrawing technologies such as typography. In those applications, the two-dimensionalimage is not just a representation of a real-world object, but an independent artifact with added semantic value; two-dimensional models are therefore preferred because they give more direct control of the image than3D computer graphics, whose approach is more akin tophotography than totypography.
A large form of digital art, pixel art is created through the use ofraster graphics software, where images are edited on thepixel level. Graphics in most old (or relatively limited) computer and video games,graphing calculator games, and manymobile phone games are mostly pixel art.
Asprite is a two-dimensionalimage oranimation that is integrated into a larger scene. Initially including just graphical objects handled separately from the memorybitmap of a video display, this now includes various manners of graphical overlays.
Originally, sprites were a method of integrating unrelated bitmaps so that they appeared to be part of the normal bitmap on ascreen, such as creating an animated character that can be moved on a screen without altering thedata defining the overall screen. Such sprites can be created by either electroniccircuitry orsoftware. In circuitry, a hardware sprite is ahardware construct that employs customDMA channels to integrate visual elements with the main screen in that it super-imposes two discrete video sources. Software can simulate this through specialized rendering methods.
Vector graphics formats are complementary toraster graphics. Raster graphics is the representation of images as an array ofpixels and is typically used for the representation of photographic images.[23] Vector graphics consists of encoding information about shapes and colors that comprise the image, which can allow for more flexibility in rendering. There are instances when working with vector tools and formats is best practice, and instances when working with raster tools and formats is best practice. There are times when both formats come together. An understanding of the advantages and limitations of each technology and the relationship between them is most likely to result in efficient and effective use of tools.
Since the mid-2010s, as a result of advances indeep neural networks, models have been created which take as input a natural language description and produces as output an image matching that description. Text-to-image models generally combine alanguage model, which transforms the input text into a latent representation, and agenerative image model, which produces an image conditioned on that representation. The most effective models have generally been trained on massive amounts of image and text data scraped from the web. By 2022, the best of these models, for exampleDall-E 2 andStable Diffusion, are able to create images in a range of styles, ranging from imitations of living artists to near-photorealistic, in a matter of seconds, given powerful enough hardware.[24]
3D graphics, compared to 2D graphics, are graphics that use athree-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.
Despite these differences, 3D computer graphics rely on similaralgorithms as 2D computer graphics do in the frame and raster graphics (like in 2D) in the final rendered display. In computer graphics software, the distinction between 2D and 3D is occasionally blurred; 2D applications may use 3D techniques to achieve effects such as lighting, and primarily 3D may use 2D rendering techniques.
3D computer graphics are the same as 3D models. The model is contained within the graphical data file, apart from the rendering. However, there are differences that include the 3D model being the representation of any 3D object. Until visually displayed, a model is not graphic. Due to printing, 3D models are not only confined to virtual space. 3D rendering is how a model can be displayed. Also can be used in non-graphicalcomputer simulations and calculations.
Computer animation is the art of creating moving images via the use ofcomputers. It is a subfield of computer graphics andanimation. Increasingly it is created by means of3D computer graphics, though2D computer graphics are still widely used for stylistic, low bandwidth, and fasterreal-time rendering needs. Sometimes the target of the animation is the computer itself, but sometimes the target is anothermedium, such asfilm. It is also referred to as CGI (Computer-generated imagery or computer-generated imaging), especially when used in films.
Virtual entities may contain and be controlled by assorted attributes, such as transform values (location, orientation, and scale) stored in an object'stransformation matrix. Animation is the change of an attribute over time. Multiple methods of achieving animation exist; the rudimentary form is based on the creation and editing ofkeyframes, each storing a value at a given time, per attribute to be animated. The 2D/3D graphics software will change with each keyframe, creating an editable curve of a value mapped over time, in which results in animation. Other methods of animation includeprocedural andexpression-based techniques: the former consolidates related elements of animated entities into sets of attributes, useful for creatingparticle effects andcrowd simulations; the latter allows an evaluated result returned from a user-defined logical expression, coupled with mathematics, to automate animation in a predictable way (convenient for controlling bone behavior beyond what ahierarchy offers inskeletal system set up).
To create the illusion of movement, an image is displayed on the computerscreen then quickly replaced by a new image that is similar to the previous image, but shifted slightly. This technique is identical to the illusion of movement intelevision andmotion pictures.
In the enlarged portion of the image individual pixels are rendered as squares and can be easily seen.
In digital imaging, apixel (or picture element[25]) is a single point in araster image. Pixels are placed on a regular 2-dimensional grid, and are often represented using dots or squares. Each pixel is asample of an original image, where more samples typically provide a more accurate representation of the original. Theintensity of each pixel is variable; in color systems, each pixel typically has threesubpixels such asred, green, and blue.
Graphics arevisual representations on a surface, such as a computer screen. Examples are photographs, drawing, graphics designs,maps,engineering drawings, or other images. Graphics often combine text and illustration. Graphic design may consist of the deliberate selection, creation, or arrangement of typography alone, as in a brochure, flier, poster, web site, or book without any other element. Clarity or effective communication may be the objective, association with other cultural elements may be sought, or merely, the creation of a distinctive style.
Rendering is the generation of a 2D image from a 3D model by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texturing,lighting, andshading information as a description of the virtual scene.[26] The data contained in the scene file is then passed to a rendering program to be processed and output to adigital image orraster graphics image file. The rendering program is usually built into the computer graphics software, though others are available as plug-ins or entirely separate programs. The term "rendering" may be by analogy with an "artist's rendering" of a scene. Although the technical details of rendering methods vary, the general challenges to overcome in producing a 2D image from a 3D representation stored in a scene file are outlined as thegraphics pipeline along a rendering device, such as aGPU. A GPU is a device able to assist the CPU in calculations. If a scene is to look relatively realistic and predictable under virtual lighting, the rendering software should solve therendering equation. The rendering equation does not account for all lighting phenomena, but is a general lighting model for computer-generated imagery. 'Rendering' is also used to describe the process of calculating effects in a video editing file to produce final video output.
3D projection
3D projection is a method of mapping three dimensional points to a two dimensional plane. As most current methods for displaying graphical data are based on planar two dimensional media, the use of this type of projection is widespread. This method is used in most real-time 3D applications and typically usesrasterization to produce the final image.
Example of shadingShading refers todepicting depth in3D models or illustrations by varying levels ofdarkness. It is a process used in drawing for depicting levels of darkness on paper by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas. There are various techniques of shading includingcross hatching where perpendicular lines of varying closeness are drawn in a grid pattern to shade an area. The closer the lines are together, the darker the area appears. Likewise, the farther apart the lines are, the lighter the area appears. The term has been recently generalized to mean thatshaders are applied.
Texture mapping
Texture mapping is a method for adding detail, surface texture, or colour to acomputer-generated graphic or3D model. Its application to 3D graphics was pioneered byEdwin 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.[27]Procedural textures (created from adjusting parameters of an underlying algorithm that produces an output texture), andbitmap textures (created in animage editing application or imported from adigital 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 asUV mapping (arbitrary, manual layout of texture coordinates) forpolygon surfaces, whilenon-uniform rational B-spline (NURB) surfaces have their own intrinsicparameterization used as texture coordinates. Texture mapping as a discipline also encompasses techniques for creatingnormal maps andbump maps that correspond to a texture to simulate height andspecular maps to help simulate shine and light reflections, as well asenvironment mapping to simulate mirror-like reflectivity, also called gloss.
Anti-aliasing
Rendering resolution-independent entities (such as 3D models) for viewing on a raster (pixel-based) device such as aliquid-crystal display orCRT television inevitably causesaliasing artifacts mostly along geometric edges and the boundaries of texture details; these artifacts are informally called "jaggies". Anti-aliasing methods rectify such problems, resulting in imagery more pleasing to the viewer, but can be somewhat computationally expensive. Various anti-aliasing algorithms (such assupersampling) are able to be employed, then customized for the most efficient rendering performance versus quality of the resultant imagery; a graphics artist should consider this trade-off if anti-aliasing methods are to be used. A pre-anti-aliasedbitmap texture being displayed on a screen (or screen location) at a resolution different from the resolution of the texture itself (such as a textured model in the distance from the virtual camera) will exhibit aliasing artifacts, while anyprocedurally defined texture will always show aliasing artifacts as they are resolution-independent; techniques such asmipmapping andtexture filtering help to solve texture-related aliasing problems.
Volume renderedCT scan of a forearm with different colour schemes for muscle, fat, bone, and blood
Usually these are acquired in a regular pattern (e.g., one slice every millimeter) and usually have a regular number of imagepixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, orvoxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel.
3D modeling is the process of developing a mathematical,wireframe representation of any three-dimensional object, called a "3D model", via specialized software. Models may be created automatically or manually; the manual modeling process of preparing geometric data for 3D computer graphics is similar toplastic arts such assculpting. 3D models may be created using multiple approaches: use of NURBs to generate accurate and smooth surface patches,polygonal mesh modeling (manipulation of faceted geometry), or polygonal meshsubdivision (advanced tessellation of polygons, resulting in smooth surfaces similar to NURB models). A 3D model can be displayed as a two-dimensional image through a process called3D rendering, used in acomputer simulation of physical phenomena, or animated directly for other purposes. The model can also be physically created using3D Printing devices.
Donald P. Greenberg is a leading innovator in computer graphics. Greenberg has authored hundreds of articles and served as a teacher and mentor to many prominent computer graphic artists, animators, and researchers such asRobert L. Cook,Marc Levoy,Brian A. Barsky, andWayne Lytle. Many of his former students have won Academy Awards for technical achievements and several have won theSIGGRAPH Achievement Award. Greenberg was the founding director of the NSF Center for Computer Graphics and Scientific Visualization.
Noll was one of the first researchers to use adigital computer to create artistic patterns and to formalize the use of random processes in the creation ofvisual arts. He began creating digital art in 1962, making him one of the earliest digital artists. In 1965, Noll along withFrieder Nake andGeorg Nees were the first to publicly exhibit theircomputer art. During April 1965, the Howard Wise Gallery exhibited Noll's computer art along with random-dot patterns byBela Julesz.
Jack Bresenham is a former professor of computer science. He developed theBresenham's line algorithm, his most well-known invention in 1962. He retired from 27 years of service atIBM as a Senior Technical Staff Member, taught for 16 years atWinthrop University and has ninepatents.
Thestudy of computer graphics is a sub-field ofcomputer science which studies methods for digitally synthesizing and manipulating visual content. Although the term often refers to three-dimensional computer graphics, it also encompasses two-dimensional graphics andimage processing.
As anacademic discipline, computer graphics studies the manipulation of visual and geometric information using computational techniques. It focuses on themathematical andcomputational foundations of image generation and processing rather than purelyaesthetic issues. Computer graphics is often differentiated from the field ofvisualization, although the two fields have many similarities.
^Theuncanny 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.
^Peddie, Jon (2013).The History of Visual Magic in Computers: How Beautiful Images are Made in CAD, 3D, VR and AR. Springer. p. 101.ISBN978-1447149316.
.jpg)
![[icon]](/mt/?noimg=&dark=on&url=https%3a%2f%2fwikipedia.org%2fwiki%2fFile%3aWiki_letter_w_cropped.svg)
.webp)
