Computer graphics (computer science)

Computer graphics 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 the study of three-dimensional 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...

, it also encompasses two-dimensional 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...

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...

Overview

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.

Connected studies include:

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...
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...
Computer vision
Computer vision
Computer vision is a field that includes methods for acquiring, processing, analysing, and understanding images and, in general, high-dimensional data from the real world in order to produce numerical or symbolic information, e.g., in the forms of decisions...
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...
Computational geometry
Computational geometry
Computational geometry is a branch of computer science devoted to the study of algorithms which can be stated in terms of geometry. Some purely geometrical problems arise out of the study of computational geometric algorithms, and such problems are also considered to be part of computational...
Computational topology
Applied mathematics
Applied mathematics
Applied mathematics is a branch of mathematics that concerns itself with mathematical methods that are typically used in science, engineering, business, and industry. Thus, "applied mathematics" is a mathematical science with specialized knowledge...

Applications of computer graphics include:

Special effects
Special effect
The illusions used in the film, television, theatre, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....
Visual effects
Visual effects
Visual effects are the various processes by which imagery is created and/or manipulated outside the context of a live action shoot. Visual effects involve the integration of live-action footage and generated imagery to create environments which look realistic, but would be dangerous, costly, or...
Video games
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...

History

One of the first displays of computer animation was Futureworld
Futureworld
Futureworld is a 1976 sequel to the 1973 science fiction film Westworld. It was written by George Schenk and Mayo Simon, and directed by Richard T. Heffron. The cast included Peter Fonda, Blythe Danner, and Arthur Hill. There is also a cameo appearance by Yul Brynner in a dream sequence...

(1976), which included an 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...

of a human face and hand — produced by Ed 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....

and 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...

at the University of Utah

University 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...

.

There are several international conferences and journals where the most significant results in computer graphics are published. Among them are the 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...

and Eurographics

Eurographics

Eurographics is a Europe-wide professional Computer Graphics association. The association supports its members in advancing the state of the art in Computer Graphics and related fields such as Multimedia, Scientific Visualization and Human-Computer Interaction....

conferences and the Association for Computing Machinery

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...

(ACM) Transactions on Graphics journal. The joint Eurographics and ACM SIGGRAPH symposium series features the major venues for the more specialized sub-fields: Symposium on Geometry Processing,Symposium on Rendering, and Symposium on Computer Animation. As in the rest of computer science, conference publications in computer graphics are generally more significant than journal publications (and subsequently have lower acceptance rates).

Subfields in computer graphics

A broad classification of major subfields in computer graphics might be:

Geometry: studies ways to represent and process surfaces
Animation: studies with ways to represent and manipulate motion
Rendering: studies 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 to reproduce light transport
Imaging: studies image acquisition or image editing

Geometry

The subfield of geometry studies the representation of three-dimensional objects in a discrete digital setting. Because the appearance of an object depends largely on its exterior, boundary representation

Boundary representation

In solid modeling and computer-aided design, boundary representation—often abbreviated as B-rep or BREP—is a method for representing shapes using the limits...

s are most commonly used. Two dimensional surface

Surface

In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...

s are a good representation for most objects, though they may be non-manifold

Manifold

In mathematics , a manifold is a topological space that on a small enough scale resembles the Euclidean space of a specific dimension, called the dimension of the manifold....

. Since surfaces are not finite, discrete digital approximations are used. Polygonal meshes

Polygon mesh

A 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...

(and to a lesser extent subdivision surfaces) are by far the most common representation, although point-based representations have become more popular recently (see for instance the Symposium on Point-Based Graphics). These representations are Lagrangian, meaning the spatial locations of the samples are independent. Recently, Eulerian surface descriptions (i.e., where spatial samples are fixed) such as level set

Level set

In mathematics, a level set of a real-valued function f of n variables is a set of the formthat is, a set where the function takes on a given constant value c....

s have been developed into a useful representation for deforming surfaces which undergo many topological changes (with fluids being the most notable example).

Geometry Subfields

Implicit surface modeling - an older subfield which examines the use of algebraic surfaces, constructive solid geometry
Constructive solid geometry
Constructive solid geometry is a technique used in solid modeling. Constructive solid geometry allows a modeler to create a complex surface or object by using Boolean operators to combine objects...

, etc., for surface representation.
Digital geometry processing - surface reconstruction, simplification, fairing, mesh repair, parameterization
Mesh parameterization
Given two surfaces with the same topology, a bijective mapping between them exists. On triangular mesh surfaces, the problem of computing this mapping is called mesh parameterization. The parameter domain is the surface that the mesh is mapped onto....

, remeshing, mesh generation
Mesh generation
Mesh generation is the practice of generating a polygonal or polyhedral mesh that approximates a geometric domain. The term "grid generation" is often used interchangeably. Typical uses are for rendering to a computer screen or for physical simulation such as finite element analysis or...

, surface compression, and surface editing all fall under this heading.
Discrete differential geometry - a nascent field which defines geometric quantities for the discrete surfaces used in computer graphics.
Point-based graphics - a recent field which focuses on points as the fundamental representation of surfaces.
Subdivision surfaces
Out-of-core mesh processing - another recent field which focuses on mesh datasets that do not fit in main memory.

Animation

The subfield of animation studies descriptions for surfaces (and other phenomena) that move or deform over time. Historically, most work in this field has focused on parametric and data-driven models, but recently physical simulation has become more popular as computers have become more powerful computationally.

Subfields

Performance capture
Character animation
Physical simulation (e.g. cloth modeling
Cloth modeling
Cloth modeling is the term used for simulating cloth within a computer program; usually in the context of 3D computer graphics. The main approaches used for this may be classified into three basic types: geometric, physical, and particle/energy.- Background :...

, animation of fluid dynamics
Fluid dynamics
In physics, fluid dynamics is a sub-discipline of fluid mechanics that deals with fluid flow—the natural science of fluids in motion. It has several subdisciplines itself, including aerodynamics and hydrodynamics...

, etc.)

Rendering

Rendering generates images from a model. Rendering may simulate light transport

Light transport theory

Light transport theory deals with the mathematics behind calculating the energy transfers between media that affect visibility. This article is currently specific to light transport in rendering processes such as global illumination and HDRI....

to create realistic images or it may create images that have a particular artistic style in non-photorealistic rendering

Non-photorealistic rendering

Non-Photorealistic rendering is an area of computer graphics that focuses on enabling a wide variety of expressive styles for digital art. In contrast to traditional computer graphics, which has focused on photorealism, NPR is inspired by artistic styles such as painting, drawing, technical...

. The two basic operations in realistic rendering are transport (how much light passes from one place to another) and scattering (how surfaces interact with light). See Rendering (computer graphics)

Rendering (computer graphics)

Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...

for more information.

Transport
Transport

Light transport theory

describes how illumination in a scene gets from one place to another. Visibility

Visibility (geometry)

Visibility is a mathematical abstraction of the real-life notion of visibility.Given a set of obstacles in the Euclidean space, two points in the space are said to be visible to each other, if the line segment that joins them does not intersect any obstacles.Computation of visibility is among the...

is a major component of light transport.

Scattering
Models of scattering and shading are used to describe the appearance of a surface. In graphics these problems are often studied within the context of rendering since they can substantially affect the design of rendering algorithms. Shading can be broken down into two orthogonal issues, which are often studied independently:

scattering - how light interacts with the surface at a given point
shading - how material properties vary across the surface

The former problem refers to scattering

Scattering

Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of...

, i.e., the relationship between incoming and outgoing illumination at a given point. Descriptions of scattering are usually given in terms of a bidirectional scattering distribution function

Bidirectional scattering distribution function

The definition of the BSDF is not well standardized. The term was probably introduced in 1991 by Paul Heckbert. Most often it is used to name the general mathematical function which describes the way in which the light is scattered by a surface...

or BSDF. The latter issue addresses how different types of scattering are distributed across the surface (i.e., which scattering function applies where). Descriptions of this kind are typically expressed with a program called a shader

Shader

In 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...

. (Note that there is some confusion since the word "shader" is sometimes used for programs that describe local geometric variation.)

Other subfields

physically based rendering - concerned with generating images according to the laws of geometric optics
real time rendering
Real Time rendering
Real-time rendering is one of the interactive areas of computer graphics, it means creating synthetic images fast enough on the computer so that the viewer can interact with a virtual environment. The most common place to find real-time rendering is in video games. The rate at which images are...

- focuses on rendering for interactive applications, typically using specialized hardware like GPUs
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...
non-photorealistic rendering
Non-photorealistic rendering
Non-Photorealistic rendering is an area of computer graphics that focuses on enabling a wide variety of expressive styles for digital art. In contrast to traditional computer graphics, which has focused on photorealism, NPR is inspired by artistic styles such as painting, drawing, technical...
relighting - recent area concerned with quickly re-rendering scenes

Notable researchers in computer graphics

Jim Blinn
Jim Blinn
James 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...
Jack E. Bresenham
Jack E. Bresenham
Jack Elton Bresenham is a former professor of computer science.-Biography:He retired from 27 years of service at IBM as a Senior Technical Staff Member in 1987. He taught for 16 years at Winthrop University and has nine patents...
Loren Carpenter
Loren Carpenter
Loren C. Carpenter is a computer graphics researcher and developer. He is co-founder and chief scientist of Pixar Animation Studios. He is the co-inventor of the Reyes rendering algorithm and is one of the authors of the PhotoRealistic RenderMan software which implements Reyes and which renders...
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....
Robert L. Cook
Robert L. Cook
Robert 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...
Paul Debevec
Paul Debevec
Paul Debevec is a researcher in computer graphics at the University of Southern California's Institute for Creative Technologies. He is best known for his pioneering work in high dynamic range imaging and image-based modelling and rendering....
Ron Fedkiw
Ronald Fedkiw
Ronald Paul "Ron" Fedkiw is an associate professor in the Stanford University department of computer science and a leading researcher in the field of computer graphics, focusing on topics relating to physically based simulation of natural phenomena and level sets. His techniques have been...
James D. Foley
James D. Foley
James David Foley is a Professor and the Stephen Fleming Chair in Telecommunications in the School of Interactive Computing, and former Dean of the College of Computing at Georgia Institute of Technology from 2008-2010...

David Forsyth
David Forsyth (computer scientist)
David Forsyth is an American computer scientist and full professor at the University of Illinois at Urbana-Champaign, born in South Africa. He is married to Margaret Fleck, who is also a professor at the University of Illinois....
Henry Fuchs
Henry Fuchs
Prof. Henry Fuchs is a fellow of the American Academy of Arts and Sciences and the Association for Computing Machinery and the Federico Gil Professor of Computer Science at the University of North Carolina at Chapel Hill . He is also an adjunct professor in biomedical engineering...
Pat Hanrahan
Pat Hanrahan
Pat Hanrahan is a computer graphics researcher, the Canon USA Professor of Computer Science and Electrical Engineering in the Computer Graphics Laboratory at Stanford University....
Takeo Kanade
Takeo Kanade
is a Japanese computer scientist and one of the world's foremost researchers in computer vision. He is currently U.A. and Helen Whitaker Professor at Carnegie Mellon University...
Jim Kajiya
Jim Kajiya
Jim Kajiya is a pioneer in the field of computer graphics. He is perhaps best known for the development of the rendering equation.Kajiya received his PhD from the University of Utah in 1979, was a professor at Caltech from 1979 through 1994, and is currently a researcher at Microsoft Research.-...
Kenneth Knowlton
Marc Levoy
Marc Levoy
Marc 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....
James O'Brien
James F. O'Brien
James F. O'Brien is a computer graphics researcher and associate professor of Computer Science and Electrical Engineering at the University of California, Berkeley.-Education:...
Ken Perlin
Ken Perlin
Ken Perlin is a professor in the Department of Computer Science at New York University, founding director of the Media Research Lab at NYU, and the Director of the Games for Learning Institute. His research interests include graphics, animation, multimedia, and science education...

Przemyslaw Prusinkiewicz
Przemyslaw Prusinkiewicz
Przemyslaw Prusinkiewicz is a Polish computer scientist who advanced the idea that Fibonacci numbers in nature can be in part understood as the expression of certain algebraic constraints on free groups, specifically as certain Lindenmayer grammars...
William Reeves
William Reeves
William "Bill" Reeves is a pioneer in the field of computer graphics. He was the technical director who worked with John Lasseter on the animation breakthrough shorts: Luxo Jr and The Adventures of André and Wally B.....
James Sethian
James Sethian
James Albert Sethian is a professor of mathematics at the University of California, Berkeley, and the head of the Mathematics Group at the United States Department of Energy's Lawrence Berkeley National Laboratory....
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...
Greg Turk
Greg Turk
Greg Turk is an American-born researcher in the field of computer graphics and a Professor at the School of Interactive Computing in the College of Computing at the Georgia Institute of Technology...
Andries van Dam
Andries van Dam
Andries "Andy" van Dam is a Dutch-born American professor of computer science and former Vice-President for Research at Brown University in Providence, Rhode Island. Together with Ted Nelson he contributed to the first hypertext system, HES in the late 1960s. He co-authored Computer Graphics:...
Henrik Wann Jensen
Henrik Wann Jensen
Henrik Wann Jensen is a Danish computer graphics researcher. He is best known for developing the photon mapping technique as the subject of his PhD thesis, but has also done important research in simulating subsurface scattering and the sky....
Lance Williams
Lance Williams
Lance J. Williams is a prominent graphics researcher who made major contributions to texture map prefiltering, shadow rendering algorithms, facial animation, and antialiasing techniques...

External links

University Groups

Industry

Industrial labs doing "blue sky" graphics research include:

Major film studios notable for graphics research include:

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Overview

History

Subfields in computer graphics

Geometry

Animation

Rendering

Notable researchers in computer graphics

See also

Further reading

External links

University Groups

Industry