Computer graphics
Encyclopedia
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
created using computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s and, more generally, the representation
Representation
Representation can refer to:* Representation , one's ability to influence the political process* Representative democracy* Representation, a type of diplomatic mission...
and manipulation
Manipulation
-As underhand influence:*Crowd manipulation*Data manipulation*Market manipulation*Media manipulation*Parental manipulation*Psychological manipulation-In a physical context:*Card manipulation*Coin manipulation*Hat manipulation*Joint manipulation...
of image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
data
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
by a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
with help from specialized software
Graphics software
In computer graphics, graphics software or image editing software is a program or collection of programs that enable a person to manipulate visual images on a computer....
and hardware
Graphics hardware
Graphics hardware is a hardware that enable to produce and show computer graphics. It works in conjuntion with graphics software. Examples of graphics hardware are display devices, graphics cards and motion capture hardware....
.
The development of computer graphics has made computers easier to interact with, and better for understanding and interpreting many types of data. Developments in computer graphics have had a profound impact on many types of media and have revolutionized animation
Animation
Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
, movies and the video game industry.
Overview
The term computer graphics has been used in a broad sense to describe "almost everything on computers that is not text or sound". Typically, the term computer graphics refers to several different things:- the representationRepresentationRepresentation can refer to:* Representation , one's ability to influence the political process* Representative democracy* Representation, a type of diplomatic mission...
and manipulationPhoto manipulationPhoto manipulation is the application of image editing techniques to photographs in order to create an illusion or deception , through analog or digital means.- Types of digital photo manipulation :...
of imageImageAn image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
dataDataThe term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
by a computerComputerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem... - the various technologies used to create and manipulate images
- the imageImageAn image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
s so produced, and - the sub-field of computer scienceComputer scienceComputer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
which studies methods for digitally synthesizing and manipulating visual content, see study of computer graphicsComputer graphics (computer science)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.- Overview...
Today, computers and guns-generated images touch many people of daily life. Computer imagery is found on television, in newspapers, for example in weather reports, or for example in all kinds of medical investigation and surgical procedures. A well-constructed graph
Chart
A chart is a graphical representation of data, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart"...
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.
Many powerful tools have been developed to visualize data. Computer generated imagery can be categorized into several different types: 2D, 3D, and animated graphics. As technology has improved, 3D computer graphics have become more common, but 2D computer graphics are still widely used. Computer graphics has emerged as a sub-field of computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
which studies methods for digitally synthesizing and manipulating visual content. Over the past decade, other specialized fields have been developed like information visualization
Information visualization
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".- Overview...
, and scientific visualization
Scientific visualization
Scientific visualization is an interdisciplinary branch of science according to Friendly "primarily concerned with the visualization of three-dimensional phenomena , where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps...
more concerned with "the visualization of three dimensional
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...
phenomena (architectural, meteorological, medical, biological
Biological data visualization
Biology Data Visualization is a branch of bioinformatics concerned with the application of computer graphics, scientific visualization, and information visualization to different areas of the life sciences. This includes visualization of sequences, genomes, alignments, phylogenies, macromolecular...
, etc.), where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps with a dynamic (time) component".
History
The phrase “Computer Graphics” was coined in 1960 by William FetterWilliam Fetter
William Fetter was an American computer graphics art director. In 1964, while working for Boeing, he made the first computer model of a human body . He coined the term Computer Graphics in 1960, to describe his work at Boeing....
, a graphic designer for Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
. The field of computer graphics developed with the emergence of computer graphics hardware. Early projects like the Whirlwind
Whirlwind (computer)
The Whirlwind computer was developed at the Massachusetts Institute of Technology. It is the first computer that operated in real time, used video displays for output, and the first that was not simply an electronic replacement of older mechanical systems...
and SAGE Projects introduced the CRT
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
as a viable display and interaction interface and introduced the light pen
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
as an input device
Input device
In computing, an input device is any peripheral used to provide data and control signals to an information processing system such as a computer or other information appliance...
.
Initial 1960s developments
Further advances in computing led to greater advancements in interactive computer graphics. In 1959, the TX-2TX-2
The MIT Lincoln Laboratory TX-2 computer was the successor to the Lincoln TX-0 and was known for its role in advancing both artificial intelligence and human-computer interaction.- Specifications :...
computer was developed at MIT's Lincoln Laboratory
Lincoln Laboratory
MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense research and development center chartered to apply advanced technology to problems of national security. Research and development activities focus on long-term technology development as well as...
. 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
Ivan Sutherland
Ivan Edward Sutherland is an American computer scientist and Internet pioneer. He received the Turing Award from the Association for Computing Machinery in 1988 for the invention of Sketchpad, an early predecessor to the sort of graphical user interface that has become ubiquitous in personal...
's revolutionary Sketchpad software
Sketchpad
Sketchpad was a revolutionary computer program written by Ivan Sutherland in 1963 in the course of his PhD thesis, for which he received the Turing Award in 1988. It helped change the way people interact with computers...
. 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 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's 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, s/he does not have to worry about drawing four lines perfectly to form the edges of the box. One can simply specify that s/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 graphic
Vector graphic
Vector graphic may refer to:*Vector Graphic, a computer company*Vector graphics, a form of computer graphics*Vektor Grafix, UK based computer game development company...
s, composed of thin lines whereas modern day graphics are Raster based using pixels.set os images is called picket or dots.
Further 1960s developments
Steve Russell
Steve "Slug" Russell is a programmer and computer scientist most famous for creating Spacewar!, one of the earliest videogames, in 1961 with the fellow members of the Tech Model Railroad Club at MIT working on a DEC Digital PDP-1...
, created the first video game, Spacewar. Written for the DEC PDP-1
PDP-1
The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
, 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
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
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
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
(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
IBM 7090
The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
mainframe computer. Also at BTL, Ken Knowlton
Ken Knowlton
In 1963, Knowlton developed the BEFLIX programming language for bitmap computer-produced movies, created using an IBM 7094 computer and a Stromberg-Carlson 4020 microfilm recorder. Each frame contained eight shades of grey and a resolution of 252 x 184....
, 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
TRW
TRW Inc. was an American corporation involved in a variety of businesses, mainly aerospace, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft,...
, Lockheed-Georgia
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...
, General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
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.
Magnavox
Magnavox is a US electronics company founded by Edwin Pridham and Peter L. Jensen, who invented the moving-coil loudspeaker in 1915 at their lab in Napa, California. They formed Magnavox in 1917 in order to market their inventions....
and called the Odyssey
Magnavox Odyssey
The Magnavox Odyssey is the world's first home video game console. It was first demonstrated on May 24, 1972 and released in August of that year, predating the Atari Pong home consoles by three years....
. 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
Head-mounted display
A head-mounted display or helmet mounted display, both abbreviated HMD, is a display device, worn on the head or as part of a helmet, that has a small display optic in front of one or each eye .- Overview :...
(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.
David C. Evans
David C. Evans
David Cannon Evans was the founder of the computer science department at the University of Utah and co-founder of Evans & Sutherland, a computer firm which is known as a pioneer in the domain of computer-generated imagery.-Biography:Evans attended the University of Utah and studied electrical...
was director of engineering at Bendix Corporation
Bendix Corporation
The Bendix Corporation was an American manufacturing and engineering company which during various times in its 60 year existence made brake systems, aeronautical hydraulics, avionics, aircraft and automobile fuel control systems, radios, televisions and computers, and which licensed its name for...
'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 1968 the University 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.
In 1967 Sutherland was recruited by Evans to join the computer science program at the University of Utah. There he 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 1969, the ACM
Association for Computing Machinery
The Association for Computing Machinery is a learned society for computing. It was founded in 1947 as the world's first scientific and educational computing society. Its membership is more than 92,000 as of 2009...
initiated A Special Interest Group in Graphics (SIGGRAPH
SIGGRAPH
SIGGRAPH is the name of the annual conference on computer graphics convened by the ACM SIGGRAPH organization. The first SIGGRAPH conference was in 1974. The conference is attended by tens of thousands of computer professionals...
) which organizes conferences, graphics standards, and publications within the field of computer graphics. In 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.
1970s
Many of the most important early breakthroughs in computer graphics research occurred at the University of UtahUniversity of Utah
The University of Utah, also known as the U or the U of U, is a public, coeducational research university in Salt Lake City, Utah, United States. The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah's oldest...
in the 1970s. A student by the name of Edwin Catmull
Edwin Catmull
Dr. Edwin Earl Catmull, Ph.D. is a computer scientist and current president of Walt Disney Animation Studios and Pixar Animation Studios. As a computer scientist, Catmull has contributed to many important developments in computer graphics....
started at the University of Utah in 1970 and 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
Fred Parke
Frederic Ira Parke graduated from the University of Utah with a BS degree in physics in 1965. He was then a graduate student of the University of Utah College of Engineering where he received his MS and PhD in computer science. Parke was the creator of the first CG physically modeled human face...
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
John Warnock
John Edward Warnock is an American computer scientist best known as the co-founder with Charles Geschke of Adobe Systems Inc., the graphics and publishing software company. Dr. Warnock was President of Adobe for his first two years and Chairman and CEO for his remaining sixteen years at the company...
was one of those early pioneers; he would later found Adobe Systems
Adobe Systems
Adobe Systems Incorporated is an American computer software company founded in 1982 and headquartered in San Jose, California, United States...
and create a revolution in the publishing world with his PostScript
PostScript
PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...
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 would later found 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.
1980s
In the 1980s, 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. In the late 1980s, SGISilicon Graphics
Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
computers were used to create some of the first fully computer-generated short films at Pixar
Pixar
Pixar Animation Studios, pronounced , is an American computer animation film studio based in Emeryville, California. The studio has earned 26 Academy Awards, seven Golden Globes, and three Grammy Awards, among many other awards and acknowledgments. Its films have made over $6.3 billion worldwide...
. 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
Multimedia
Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which use only rudimentary computer display such as text-only, or...
technology.
1990s
3D graphics became more popular in the 1990s in gaming, multimediaMultimedia
Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which use only rudimentary computer display such as text-only, or...
and animation
Animation
Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
. At the end of the 80s and 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 J.-Y. Grall, Georges Lacroix and Renato (studio Fantome, 1990-1993) and Quarxs
Quarxs
Quarxs created between 1990 and 1993, was one of the earliest computer animated series. It predated ReBoot.Each episode was made in HDTV and no more than three minutes long. Only twelve episodes of the original series of 100 have been created...
, the first HDTV computer graphics series by Maurice Benayoun
Maurice Benayoun
Maurice Benayoun is a French pioneer new-media artist and theorist based in Paris. His work employs various media, including video, immersive virtual reality, the Web, wireless technology, performance, large-scale urban art installations and interactive exhibitions.-Biography:Born in Mascara,...
and François Schuiten
François Schuiten
Baron François Schuiten is a Belgian comic book artist. He is best known for drawing the series Les Cités Obscures.-Biography:François Schuiten was born in Brussels, Belgium in 1956....
(studio Z-A production, 1991-1993). In 1995, Toy Story
Toy Story
Toy Story is a 1995 American computer-animated film released by Walt Disney Pictures. It is Pixar's first feature film as well as the first ever feature film to be made entirely with CGI. The film was directed by John Lasseter and featuring the voices of Tom Hanks and Tim Allen...
, the first full-length computer-generated animation film, was released in cinemas worldwide. In 1996, Quake, one of the first fully 3D game
Game
A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...
s, was released. Since then, computer graphics have only become more detailed and realistic, due to more powerful graphics hardware and 3D modeling software.
Two-dimensional
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
are the computer-based generation of digital image
Digital image
A digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
s—mostly from two-dimensional models, such as 2D geometric model
2D geometric model
A 2D geometric model is a geometric model of an object as two-dimensional figure, usually on the Euclidean or Cartesian plane.Even though all material objects are three-dimensional, a 2D geometric model is often adequate for certain flat objects, such as paper cut-outs and machine parts made of...
s, text, and digital images, and by techniques specific to them.
2D computer graphics are mainly used in applications that were originally developed upon traditional printing
Printing
Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
and drawing
Drawing
Drawing is a form of visual art that makes use of any number of drawing instruments to mark a two-dimensional medium. Common instruments include graphite pencils, pen and ink, inked brushes, wax color pencils, crayons, charcoal, chalk, pastels, markers, styluses, and various metals .An artist who...
technologies, such as typography
Typography
Typography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...
, cartography
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...
, technical drawing
Technical drawing
Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....
, advertising
Advertising
Advertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...
, etc.. In those applications, the two-dimensional image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
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 than 3D computer graphics
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
, whose approach is more akin to photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
than to typography
Typography
Typography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...
.
Pixel art
Pixel artPixel art
Pixel art is a form of digital art, created through the use of raster graphics software, where images are edited on the pixel level. Graphics in most old computer and video games, graphing calculator games, and many mobile phone games are mostly pixel art.- History :The term pixel art was first...
is a form of digital art
Digital art
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...
, created through the use of raster graphics
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
software, where images are edited on the pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
level. Graphics in most old (or relatively limited) computer and video games, graphing calculator
Graphing calculator
A graphing calculator typically refers to a class of handheld calculators that are capable of plotting graphs, solving simultaneous equations, and performing numerous other tasks with variables...
games, and many mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
games are mostly pixel art.
Vector graphics
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
formats are complementary to raster graphics
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
, which is the representation of images as an array of pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, as it is typically used for the representation of photographic images Vector graphics consists in 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.
Three-dimensional
3D computer graphics3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
in contrast to 2D computer graphics
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images. Such images may be for later display or for real-time viewing.
Despite these differences, 3D computer graphics rely on many of the same algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
s as 2D computer vector graphics
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
in the wire frame model
Wire frame model
A wire frame model is a visual presentation of a three dimensional or physical object used in 3D computer graphics. It is created by specifying each edge of the physical object where two mathematically continuous smooth surfaces meet, or by connecting an object's constituent vertices using straight...
and 2D computer raster graphics
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
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 often referred to as 3D models. Apart from the rendered graphic, the model is contained within the graphical data file. However, there are differences. A 3D model is the mathematical
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
representation of any three-dimensional
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...
object. A model is not technically a graphic until it is visually displayed. Due to 3D printing
3D printing
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is...
, 3D models are not confined to virtual space. A model can be displayed visually as a two-dimensional image through a process called 3D rendering
3D rendering
3D rendering is the 3D computer graphics process of automatically converting 3D wire frame models into 2D images with 3D photorealistic effects on a computer.-Rendering methods:...
, or used in non-graphical computer simulation
Computer simulation
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...
s and calculations. There are some 3D computer graphics software
3D computer graphics software
3D computer graphics software refers to programs used to create 3D computer-generated imagery. This article covers only some of the software used.-Uses:...
for users to create 3D images.
Computer animation
Computer animation
Computer animation is the process used for generating animated images by using computer graphics. The more general term computer generated imagery encompasses both static scenes and dynamic images, while computer animation only refers to moving images....
is the art of creating moving images via the use of computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s. It is a subfield of computer graphics and animation
Animation
Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
. Increasingly it is created by means of 3D computer graphics
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
, though 2D computer graphics
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
are still widely used for stylistic, low bandwidth, and faster real-time rendering needs. Sometimes the target of the animation is the computer itself, but sometimes the target is another medium, such as film
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
. It is also referred to as CGI (Computer-generated imagery
Computer-generated imagery
Computer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
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's transformation 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 of keyframes, each storing a value at a given time, per attribute to be animated. The 2D/3D graphics software will interpolate
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....
between keyframes, creating an editable curve of a value mapped over time, resulting in animation. Other methods of animation include procedural
Procedural animation
A procedural animation is a type of computer animation, used to automatically generate animation in real-time to allow for a more diverse series of actions than could otherwise be created using predefined animations....
and expression
Expression (mathematics)
In mathematics, an expression is a finite combination of symbols that is well-formed according to rules that depend on the context. Symbols can designate numbers , variables, operations, functions, and other mathematical symbols, as well as punctuation, symbols of grouping, and other syntactic...
-based techniques: the former consolidates related elements of animated entities into sets of attributes, useful for creating particle
Particle system
The term particle system refers to a computer graphics technique to simulate certain fuzzy phenomena, which are otherwise very hard to reproduce with conventional rendering techniques...
effects and crowd simulation
Crowd simulation
Crowd simulation is the process of simulating the movement of a large number of objects or characters, now often appearing in 3D computer graphics for film...
s; 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 a hierarchy
Hierarchy
A hierarchy is an arrangement of items in which the items are represented as being "above," "below," or "at the same level as" one another...
offers in skeletal system
Skeletal animation
Skeletal animation is a technique in computer animation in which a character is represented in two parts: a surface representation used to draw the character and a hierarchical set of interconnected bones used to animate the mesh...
set up).
To create the illusion of movement, an image is displayed on the computer screen
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
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 in television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
and motion pictures
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
.
Concepts and principles
Images are typically produced by opticalOptics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
devices;such as camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
s, mirror
Mirror
A mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...
s, lenses
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...
, telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s, microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
s, etc. and natural objects and phenomena, such as the human eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
or water surfaces.
A digital image
Digital image
A digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
is a representation of a two-dimensional image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
in binary format as a sequence of ones and zeros. Digital images include both vector
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
images and raster
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
images, but raster images are more commonly used.
Pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
(or picture element) is a single point in a raster image. Pixels are normally arranged in a regular 2-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image, where more samples typically provide a more accurate representation of the original. The intensity
Intensity (physics)
In physics, intensity is a measure of the energy flux, averaged over the period of the wave. The word "intensity" here is not synonymous with "strength", "amplitude", or "level", as it sometimes is in colloquial speech...
of each pixel is variable; in color systems, each pixel has typically three
components such as red, green, and blue
RGB color model
The RGB color model is an additive color model in which red, green, and blue light is added together in various ways to reproduce a broad array of colors...
.
Graphics
GraphicsGraphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
are visual presentations on some surface, such as a wall, canvas
Canvas
Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...
, computer screen, paper, or stone to brand
Brand
The American Marketing Association defines a brand as a "Name, term, design, symbol, or any other feature that identifies one seller's good or service as distinct from those of other sellers."...
, inform, illustrate, or entertain. Examples are photograph
Photograph
A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...
s, drawings, line art
Line art
Line art is any image that consists of distinct straight and curved lines placed against a background, without gradations in shade or hue to represent two-dimensional or three-dimensional objects...
, graphs
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
, diagrams, typography
Typography
Typography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...
, number
Number
A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers....
s, symbols, geometric designs, maps
MAPS
Maps is the plural of map, a visual representation of an area.As an acronym, MAPS may refer to:* Mail Abuse Prevention System, an organisation that provides anti-spam support...
, engineering drawings, or other image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
s. Graphics often combine text, illustration
Illustration
An illustration is a displayed visualization form presented as a drawing, painting, photograph or other work of art that is created to elucidate or dictate sensual information by providing a visual representation graphically.- Early history :The earliest forms of illustration were prehistoric...
, and color
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
. 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
Rendering is the process of generating an image from a model (or models in what collectively could be called a scene file), by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, textureTexture mapping
Texture mapping is a method for adding detail, surface texture , or color to a computer-generated graphic or 3D model. Its application to 3D graphics was pioneered by Dr Edwin Catmull in his Ph.D. thesis of 1974.-Texture mapping:...
, lighting
Lighting
Lighting or illumination is the deliberate application of light to achieve some practical or aesthetic effect. Lighting includes the use of both artificial light sources such as lamps and light fixtures, as well as natural illumination by capturing daylight...
, and shading
Shading
Shading refers to depicting depth perception in 3D models or illustrations by varying levels of darkness.-Drawing:Shading 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...
information as a description of the virtual scene. The data contained in the scene file is then passed to a rendering program to be processed and output to a digital image
Digital image
A digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
or raster graphics
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
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. Though 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 the graphics pipeline
Graphics pipeline
In 3D computer graphics, the terms graphics pipeline or rendering pipeline most commonly refers to the current state of the art method of rasterization-based rendering as supported by commodity graphics hardware. The graphics pipeline typically accepts some representation of a three-dimensional...
along a rendering device, such as a GPU
Graphics processing unit
A graphics processing unit or GPU is a specialized circuit designed to rapidly manipulate and alter memory in such a way so as to accelerate the building of images in a frame buffer intended for output to a display...
. A GPU is a purpose-built device able to assist a CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
in performing complex rendering calculations. If a scene is to look relatively realistic and predictable under virtual lighting, the rendering software should solve the rendering equation
Rendering equation
In computer graphics, the rendering equation is an integral equation in which the equilibrium radiance leaving a point is given as the sum of emitted plus reflected radiance under a geometric optics approximation. It was simultaneously introduced into computer graphics by David Immel et al. and...
. 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 projection3D projection3D projection is any 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, especially in computer graphics, engineering and drafting.-...
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, especially in computer graphics, engineering and drafting.
Ray tracing
- Ray tracing is a technique for generating an imageDigital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
by tracing the path of lightLightLight or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
through pixelPixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s in an image planeImage planeIn 3D computer graphics, the image plane is that plane in the world which is identified with the plane of the monitor. If one makes the analogy of taking a photograph to rendering a 3D image, the surface of the film is the image plane. In this case, the viewing transformation is a projection that...
. The technique is capable of producing a very high degree of photorealismPhotorealismPhotorealism is the genre of painting based on using the camera and photographs to gather information and then from this information creating a painting that appears photographic...
; usually higher than that of typical scanline renderingScanline renderingScanline rendering is an algorithm for visible surface determination, in 3D computer graphics,that works on a row-by-row basis rather than a polygon-by-polygon or pixel-by-pixel basis...
methods, but at a greater computational cost.
Shading
- ShadingShadingShading refers to depicting depth perception in 3D models or illustrations by varying levels of darkness.-Drawing:Shading 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...
refers to depicting depth in 3D models or illustrations by varying levels of darknessDarknessDarkness, in contrast with brightness, is a relative absence of visible light. It is the appearance of black in a color space. When light is not present, rod and cone cells within the eye are not stimulated. This lack of stimulation means photoreceptor cells are unable to distinguish color...
. 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 including cross hatchingHatchingHatching is an artistic technique used to create tonal or shading effects by drawing closely spaced parallel lines...
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 that shaderShaderIn the field of computer graphics, a shader is a computer program that is used primarily to calculate rendering effects on graphics hardware with a high degree of flexibility...
s are applied.
Texture mapping
- Texture mappingTexture mappingTexture mapping is a method for adding detail, surface texture , or color to a computer-generated graphic or 3D model. Its application to 3D graphics was pioneered by Dr Edwin Catmull in his Ph.D. thesis of 1974.-Texture mapping:...
is a method for adding detail, surface texture, or colour to a computer-generated graphicComputer-generated imageryComputer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
or 3D model. Its application to 3D graphics was pioneered by Dr Edwin CatmullEdwin CatmullDr. Edwin Earl Catmull, Ph.D. is a computer scientist and current president of Walt Disney Animation Studios and Pixar Animation Studios. As a computer scientist, Catmull has contributed to many important developments in computer graphics....
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. Procedural textureProcedural textureA procedural texture is a computer generated image created using an algorithm intended to create a realistic representation of natural elements such as wood, marble, granite, metal, stone, and others....
s (created from adjusting parameters of an underlying algorithm that produces an output texture), and bitmap texturesBitmapIn computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to...
(created in an image editingImage editingImage editing encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any...
application or imported from a digital cameraDigital cameraA digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...
) 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 mappingUV mappingUV mapping is the 3D modeling process of making a 2D image representation of a 3D model.-UV mapping:This process projects a texture map onto a 3D object...
(arbitrary, manual layout of texture coordinates) for polygon surfacesPolygon meshA polygon mesh or unstructured grid is a collection of vertices, edges and faces that defines the shape of a polyhedral object in 3D computer graphics and solid modeling...
, while NURBS surfaces have their own intrinsic parameterization used as texture coordinates.
Anti-aliasing
- Rendering resolution-independent entities (such as 3D models) for viewing on a raster (pixel-based) device such as a LCD display or CRT televisionCathode ray tubeThe cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
inevitably causes aliasing artifactsAliasingIn signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...
mostly along geometric edges and the boundaries of texture details; these artifacts are informally called "jaggiesJaggies"Jaggies" is the informal name for artifacts in raster images, most frequently from aliasing, which in turn is often caused by non-linear mixing effects producing high-frequency components and/or missing or poor anti-aliasing filtering prior to sampling....
". 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 as supersamplingSupersamplingSupersampling is an antialiasing technique, the process of eliminating jagged and pixelated edges . It is a method of smoothing images rendered in computer games or other programs that generate imagery.-Overview:...
) 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-aliased bitmap textureBitmapIn computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to...
being displayed on a screen (or screen location) at a resolution different than the resolution of the texture itself (such as a textured model in the distance from the virtual camera) will exhibit aliasing artifacts, while any procedurally-defined textureProcedural textureA procedural texture is a computer generated image created using an algorithm intended to create a realistic representation of natural elements such as wood, marble, granite, metal, stone, and others....
will always show aliasing artifacts as they are resolution-independent; techniques such as mipmapping and texture filteringTexture filteringIn computer graphics, texture filtering or texture smoothing is the method used to determine the texture color for a texture mapped pixel, using the colors of nearby texels . Mathematically, texture filtering is a type of anti-aliasing, but it filters out high frequencies from the texture fill...
help to solve texture-related aliasing problems.
Volume rendering
Volume rendering
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set.A typical 3D data set is a group of 2D slice images acquired by aCT, MRI, or MicroCT scanner....
is a technique used to display a 2D projection
3D projection
3D projection is any 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, especially in computer graphics, engineering and drafting.-...
of a 3D discretely sampled
Sampling (signal processing)
In signal processing, sampling is the reduction of a continuous signal to a discrete signal. A common example is the conversion of a sound wave to a sequence of samples ....
data set
Data set
A data set is a collection of data, usually presented in tabular form. Each column represents a particular variable. Each row corresponds to a given member of the data set in question. Its values for each of the variables, such as height and weight of an object or values of random numbers. Each...
. A typical 3D data set is a group of 2D slice images acquired by a CT or MRI
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
scanner.
Usually these are acquired in a regular pattern (e.g., one slice every millimeter) and usually have a regular number of image pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel
Voxel
A voxel is a volume element, representing a value on a regular grid in three dimensional space. This is analogous to a pixel, which represents 2D image data in a bitmap...
represented by a single value that is obtained by sampling the immediate area surrounding the voxel.
3D modeling
3D modeling3D modeling
In 3D computer graphics, 3D modeling is the process of developing a mathematical representation of any three-dimensional surface of object via specialized software. The product is called a 3D model...
is the process of developing a mathematical, wireframe
Wire frame model
A wire frame model is a visual presentation of a three dimensional or physical object used in 3D computer graphics. It is created by specifying each edge of the physical object where two mathematically continuous smooth surfaces meet, or by connecting an object's constituent vertices using straight...
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 to plastic arts such as sculpting. 3D models may be created using multiple approaches: use of NURBS
Nonuniform rational B-spline
Non-uniform rational basis spline is a mathematical model commonly used in computer graphics for generating and representing curves and surfaces which offers great flexibility and precision for handling both analytic and freeform shapes.- History :Development of NURBS began in the 1950s by...
curves to generate accurate and smooth surface patches, polygonal mesh modeling
Polygonal modeling
In 3D computer graphics, polygonal modeling is an approach for modeling objects by representing or approximating their surfaces using polygons. Polygonal modeling is well suited to scanline rendering and is therefore the method of choice for real-time computer graphics...
(manipulation of faceted geometry), or polygonal mesh subdivision
Subdivision surface
A subdivision surface, in the field of 3D computer graphics, is a method of representing a smooth surface via the specification of a coarser piecewise linear polygon mesh...
(advanced tessellation of polygons, resulting in smooth surfaces similar to NURBS models). A 3D model can be displayed as a two-dimensional image through a process called 3D rendering
3D rendering
3D rendering is the 3D computer graphics process of automatically converting 3D wire frame models into 2D images with 3D photorealistic effects on a computer.-Rendering methods:...
, used in a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
simulation
Simulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....
of physical phenomena, or animated directly for other purposes. The model can also be physically created using 3D Printing
3D printing
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is...
devices.
Pioneers in graphic design
Charles Csuri- Charles CsuriCharles CsuriCharles Csuri , aka Chuck Csuri, is a pioneer in the field of computer art and a former All American college football player.-Digital art:...
is a pioneer in computer animation and digital fine art and created the first computer art in 1964. Csuri was recognized by SmithsonianSmithsonian (magazine)Smithsonian is the official journal published by the Smithsonian Institution in Washington, D.C. The first issue was published in 1970.-History:...
as the father of digital art and computer animation, and as a pioneer of computer animation by the Museum of Modern ArtMuseum of Modern ArtThe Museum of Modern Art is an art museum in Midtown Manhattan in New York City, on 53rd Street, between Fifth and Sixth Avenues. It has been important in developing and collecting modernist art, and is often identified as the most influential museum of modern art in the world...
(MoMA) and Association for Computing MachineryAssociation for Computing MachineryThe Association for Computing Machinery is a learned society for computing. It was founded in 1947 as the world's first scientific and educational computing society. Its membership is more than 92,000 as of 2009...
-SIGGRAPHSIGGRAPHSIGGRAPH is the name of the annual conference on computer graphics convened by the ACM SIGGRAPH organization. The first SIGGRAPH conference was in 1974. The conference is attended by tens of thousands of computer professionals...
.
Donald P. Greenberg
- Donald P. GreenbergDonald P. GreenbergDonald Peter Greenberg is the Jacob Gould Schurman Professor of Computer Graphics at Cornell University.Greenberg earned his undergraduate and Ph.D. degrees from Cornell University, where he played on the tennis and soccer teams and was a member of Tau Delta Phi and the Quill and Dagger society...
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 as Robert L. CookRobert L. CookRobert L. Cook is a computer graphics researcher and developer, and the co-creator of the RenderMan rendering software. Cook was born in Knoxville, Tennessee and educated at Duke University and Cornell University. While at Cornell, Cook worked with Donald P. Greenberg. He is now Vice President of...
, Marc LevoyMarc LevoyMarc Levoy is a computer graphics researcher and Professor of Computer Science and Electrical Engineering at Stanford University. He is noted for pioneering work in volume rendering....
, and Wayne LytleWayne LytleWayne Lytle is the founder of Animusic, an American musical computer animation company.He created the piece More Bells & Whistles at Cornell University in 1990 and composed Beyond The Walls in 1996.- Background :...
. Many of his former students have won Academy Awards for technical achievements and several have won the SIGGRAPHSIGGRAPHSIGGRAPH is the name of the annual conference on computer graphics convened by the ACM SIGGRAPH organization. The first SIGGRAPH conference was in 1974. The conference is attended by tens of thousands of computer professionals...
Achievement Award. Greenberg was the founding director of the NSF Center for Computer Graphics and Scientific Visualization.
Aaron Marcus
- Aaron MarcusAaron MarcusAaron Marcus is an American user-interface and information-visualization designer, as well as a computer graphics artist.- Biography :...
is one of the first graphic designer in the world to work with computer graphics. He has written over 250 articles and written/co-written six books. He has published, lectured, tutored, and consulted internationally for more than 40 years and has been an invited keynote/plenary speaker at conferences of ACM/SIGCHI, ACM/SIGGRAPH, Usability Professionals Association (UPA). He was was named an AIGA Fellow in 2007 and was elected in 2008 to the CHI AcademyCHI AcademyThe CHI Academy is a group of researchers honored by SIGCHI, the Special Interest Group in Computer–Human Interaction of the Association for Computing Machinery. Each year, 5–7 new members are elected for having made a significant, cumulative contributions to the development of thefield of...
. He is the founder of Aaron Marcus and Associates, Inc.Aaron Marcus and Associates, Inc.Aaron Marcus and Associates, Inc. is a user interface development firm for mobile, Web, desktop, and vehicle applications in consumer and professional products/services...
, a pioneering, world-renowned design firm specializing in user-interface/user-experience development applications.
A. Michael Noll
- NollA. Michael NollA. Michael Noll is an American engineer, and professor emeritus at the Annenberg School for Communication at the University of Southern California. He was a very early pioneer in digital computer art and 3D animation and tactile communication.- Biography :Noll has a B.S.E.E...
was one of the first researchers to use a digitalDigitalA digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
computerComputerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
to create artistic patterns and to formalize the use of random processes in the creation of visual artsVisual artsThe visual arts are art forms that create works which are primarily visual in nature, such as ceramics, drawing, painting, sculpture, printmaking, design, crafts, and often modern visual arts and architecture...
. 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 JuleszBéla JuleszBéla Julesz was a visual neuroscientist and experimental psychologist in the fields of visual and auditory perception.Julesz was the originator of random dot stereograms which led to the creation of autostereograms...
.
- Jim BlinnJim BlinnJames F. Blinn is a computer scientist who first became widely known for his work as a computer graphics expert at NASA's Jet Propulsion Laboratory , particularly his work on the pre-encounter animations for the Voyager project, his work on the Carl Sagan Cosmos documentary series and the research...
- ArambiletArambiletAngel Luis Arambilet Alvarez [ARAMBILET] is a writer, screenplayer, painter, graphic artist, filmmaker and systems engineer....
- Benoît B. Mandelbrot
- Henri GouraudHenri GouraudHenri Gouraud may refer to:*Henri Gouraud *Henri Gouraud...
- Bui Tuong PhongBui Tuong PhongBui Tuong Phong was a Vietnamese-born computer graphics researcher and pioneer. His publications are most often referred to using his family name, Bùi, which comes before his given name by Vietnamese name convention, but his inventions are remembered under his given name Phong, since it is...
- Pierre BézierPierre BézierPierre Étienne Bézier was a French engineer and one of the founders of the fields of solid, geometric and physical modeling as well as in the field of representing curves, especially in CAD/CAM systems...
- Paul de CasteljauPaul de CasteljauPaul de Casteljau is a French physicist and mathematician. In 1959, while working at Citroën, he developed an algorithm for computation of Bézier curves, which would later be formalized and popularized by engineer Pierre Bézier...
- Daniel J. SandinDaniel J. SandinDaniel J. Sandin is a video and computer graphics artist/researcher. He is a Professor Emeritus of the School of Art & Design, University of Illinois at Chicago, and Co-director of the Electronic Visualization Laboratory at the University of Illinois at Chicago...
- Alvy Ray SmithAlvy Ray SmithAlvy Ray Smith III is an American engineer and noted pioneer in computer graphics. He is a co-founder of the animation studio Pixar.- Life and career :...
- Ton RoosendaalTon RoosendaalTon Roosendaal is a Dutch software developer. He is known as the original creator of the open-source 3D creation suite Blender, as chairman of the Blender Foundation, and for pioneering large scale open-content projects...
- Ivan SutherlandIvan SutherlandIvan Edward Sutherland is an American computer scientist and Internet pioneer. He received the Turing Award from the Association for Computing Machinery in 1988 for the invention of Sketchpad, an early predecessor to the sort of graphical user interface that has become ubiquitous in personal...
- Steve RussellSteve RussellSteve "Slug" Russell is a programmer and computer scientist most famous for creating Spacewar!, one of the earliest videogames, in 1961 with the fellow members of the Tech Model Railroad Club at MIT working on a DEC Digital PDP-1...
- Ed Catmull
- Fred ParkeFred ParkeFrederic Ira Parke graduated from the University of Utah with a BS degree in physics in 1965. He was then a graduate student of the University of Utah College of Engineering where he received his MS and PhD in computer science. Parke was the creator of the first CG physically modeled human face...
The study of computer graphics
The study of computer graphicsComputer graphics (computer science)
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.- Overview...
is a sub-field of computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
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 and image processing
Image processing
In electrical engineering and computer science, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame; the output of image processing may be either an image or, a set of characteristics or parameters related to the image...
.
As an academic discipline, computer graphics studies the manipulation of visual and geometric information using computational techniques. It focuses on the mathematical and computational foundations of image generation and processing rather than purely aesthetic issues. Computer graphics is often differentiated from the field of visualization
Visualization (graphic)
Visualization is any technique for creating images, diagrams, or animations to communicate a message. Visualization through visual imagery has been an effective way to communicate both abstract and concrete ideas since the dawn of man...
, although the two fields have many similarities.
Applications
Computer graphics may be used in the following areas:- Computational biologyComputational biologyComputational 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 physicsComputational physicsComputational physics is the study and implementation of numerical algorithms to solve problems in physics for which a quantitative theory already exists...
- Computer-aided designComputer-aided designComputer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
- Computer simulationComputer simulationA 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 artDigital artDigital 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...
- EducationEducationEducation in its broadest, general sense is the means through which the aims and habits of a group of people lives on from one generation to the next. Generally, it occurs through any experience that has a formative effect on the way one thinks, feels, or acts...
- Graphic designGraphic designGraphic design is a creative process – most often involving a client and a designer and usually completed in conjunction with producers of form – undertaken in order to convey a specific message to a targeted audience...
- Infographics
- Information visualizationInformation visualizationInformation 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".- Overview...
- Rational drug design
- Scientific visualizationScientific visualizationScientific visualization is an interdisciplinary branch of science according to Friendly "primarily concerned with the visualization of three-dimensional phenomena , where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps...
- Video Games
- Virtual realityVirtual realityVirtual reality , also known as virtuality, 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 designWeb designWeb design is the process of planning and creating a website. Text, images, digital media and interactive elements are used by web designers to produce the page seen on the web browser...
Further reading
- David Rogers (1998). Procedural Elements for Computer Graphics. McGraw-Hill.
- James D. Foley, Andries Van Dam, Steven K. Feiner and John F. Hughes (1995). Computer Graphics: Principles and Practice. Addison-Wesley
- Donald Hearn and M. Pauline Baker (1994). Computer Graphics. Prentice-Hall.
- Francis S. Hill (2001). Computer Graphics. Prentice Hall.
- John Lewell (1985). Computer Graphics: A Survey of Current Techniques and Applications. Van Nostrand Reinhold.
- Jeffrey J. McConnell (2006). Computer Graphics: Theory Into Practice. Jones & Bartlett Publishers.
- R. D. Parslow, R. W. Prowse, Richard Elliot Green (1969). Computer Graphics: Techniques and Applications.
- Peter Shirley and others. (2005). Fundamentals of computer graphics. A.K. Peters, Ltd.
- M. Slater, A. Steed, Y. Chrysantho (2002). Computer graphics and virtual environments: from realism to real-time. Addison-Wesley