Computer graphics is a sub-field of computer science and is concerned with digitally synthesizing and manipulating visual content. Computer science (or computing science) is the study and the Science of the theoretical foundations of Information and Computation and their Although the term often refers to three-dimensional computer graphics, it also encompasses two-dimensional graphics and image processing. Computer graphics is often differentiated from the field of visualization, although the two have many similarities. See also Visualization and Information graphics Visualization is any technique for creating Images Diagrams or

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

1. Geometry: studies ways to represent and process surfaces
2. Animation: studies with ways to represent and manipulate motion
3. Rendering: studies algorithms to reproduce light transport
4. Imaging: studies image acquisition or image editing

The Utah teapot

Definition

Computer graphics broadly studies the manipulation of visual and geometric information using computational techniques. The Utah teapot or Newell teapot is a 3D model which has become a standard reference object (and something of an In-joke) in the Computer graphics Computer graphics as an academic discipline focuses on the mathematical and computational foundations of image generation and processing rather than purely aesthetic issues.

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 the exterior of the object, boundary representations are most common in computer graphics. In Solid modeling and Computer-aided design, boundary representation &mdashoften abbreviated as B-rep or BREP &mdashis a method for representing Two dimensional surfaces are a good analogy for the objects most often used in graphics, though quite often these objects are non-manifold. In Mathematics, specifically in Topology, a surface is a Two-dimensional Manifold. A manifold is a mathematical space in which every point has a neighborhood which resembles Euclidean space, but in which the global structure may be Since surfaces are not finite, a discrete digital approximation is required: polygonal meshes (and to a lesser extent subdivision surfaces) are by far the most common representation, although point-based representations have been gaining some popularity in recent years (see the Symposium on Point-Based Graphics, for instance). 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 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 These representations are Lagrangian, meaning the spatial locations of the samples are independent. In recent years, however, Eulerian surface descriptions (i. e. , where spatial samples are fixed) such as level sets have been developed into a useful representation for deforming surfaces which undergo many topological changes (with fluids being the most notable example^[1]). In Mathematics, a level set of a real -valued function f of n variables is a set of the form { ( x 1 FLUID ( F ast L ight '''U'''ser '''I'''nterface D esigner is a graphical editor that is used to produce FLTK Source code

Subfields

• Constructive solid geometry - Process by which complicated objects are modelled with implicit geometric objects and boolean operations
• Discrete differential geometry - a nascent field which defines geometric quantities for the discrete surfaces used in computer graphics. Constructive solid geometry (CSG is a technique used in Solid modeling. ^[2]
• Digital geometry processing - surface reconstruction, simplification, fairing, mesh repair, parameterization, remeshing, mesh generation, surface compression, and surface editing all fall under this heading. A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly its appearance (i Mesh generation refers to the practice of generating a polygonal or polyhedral mesh that approximates a geometric domain ^[3][4][5]
• 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. 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

Animation

The subfield of animation studies descriptions for surfaces (and other phenomena) that move or deform over time. Historically most interest in this area has been focused on parametric and data-driven models, but in recent years physical simulation has experienced a renaissance due to the growing computational capacity of modern machines. Dynamical simulation, in Computational physics, is the Simulation of systems of objects that are free to move usually in three dimensions according to Newton's

Subfields

• Performance capture
• Character animation
• Physical simulation (e. g. cloth modeling, animation of fluid dynamics, etc. Cloth modeling is the term used for simulating cloth within a computer program usually in the realm of Computer graphics. Fluid dynamics is the sub-discipline of Fluid mechanics dealing with fluid flow: Fluids ( Liquids and Gases in motion )

Rendering

Rendering converts a model into an image either by simulating light transport to get physically-based photorealistic images, or by applying some kind of style as in non-photorealistic rendering. Light transport theory deals with the mathematics behind calculating the energy transfers between media that affect visibility Non-photorealistic rendering (NPR is an area of Computer graphics that focuses on enabling a wide variety of expressive styles for digital art The two basic operations in realistic rendering are transport (how much light gets from one place to another) and scattering (how surfaces interact with light). See Rendering (computer graphics) for more information. Rendering is the process of generating an image from a model, by means of computer programs

Transport

Transport describes how illumination in a scene gets from one place to another. Light transport theory deals with the mathematics behind calculating the energy transfers between media that affect visibility Visibility is a major component of light transport. Visibility is a mathematical abstraction of the real-life notion of Visibility.

Scattering

Models of scattering and shading are used to describe the appearance of a surface. Although these issues may seem like problems all on their own, they are studied almost exclusively within the context of rendering. Shading can be broken down into two orthogonal issues, which are often studied independently:

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

The former problem refers to scattering, i. Scattering is a general physical process whereby some forms of Radiation, such as Light, Sound or moving particles for example are forced to deviate from 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 or BSDF. The definition of the BSDF ( Bidirectional scattering distribution function) is not well standardized 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. A shader in the field of Computer graphics is a set of software instructions which is used by the graphic resources primarily to perform rendering effects (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 - focuses on rendering for interactive applications, typically using specialized hardware like GPUs
• non-photorealistic rendering
• relighting - recent area concerned with quickly re-rendering scenes

History

One of the first displays of computer animation was Futureworld (1976), which included an animation of a human face and hand — produced by Ed Catmull and Fred Parke at the University of Utah. Non-photorealistic rendering (NPR is an area of Computer graphics that focuses on enabling a wide variety of expressive styles for digital art Futureworld is a 1976 sequel to the 1973 Science fiction film Westworld. The bouncing ball animation (below consists of these 6 frames Edwin Catmull, PhD (born 1945 in Parkersburg, West Virginia) is an Academy Award winning Computer scientist and current president of Walt Frederick I Parke is a University of Utah graduate and creator of the first CG physically-modeled human face The University of Utah (referred to locally as ' The U' or ' the U of U') is a publicly funded Research university in Salt Lake

There are several international conferences and journals where the most significant results in computer graphics are published. Among them are the SIGGRAPH and Eurographics conferences and the Association for Computing Machinery (ACM) Transactions on Graphics journal. SIGGRAPH (short for S pecial I nterest G roup on GRAPH ics and Interactive Techniques is the name of the annual conference on Computer graphics Eurographics is a Europe-wide professional Computer Graphics association The Association for Computing Machinery, or ACM, was founded in 1947 as the world's first scientific and educational Computing society 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)^[6][7][8].

An extensive history of computer graphics can be found at this page.

Applications

• Digital art
• Special effects
• Visual effects
• Video games

Connected studies

• Computer vision
• Image processing
• Computational Geometry
• Computational Topology

Computer graphics research groups

Research

The number of computer science institutions working in computer graphics research has grown rapidly over the past two decades. Digital art most commonly refers to Art created on a Computer in Digital form The illusions used in the Film, Television, Theater, or Entertainment industries to simulate the imagined events in a story are traditionally called Visual effects (commonly shortened to Visual F/X or VFX) are the various processes by which imagery is created and/or manipulated outside the context of a Live A video game is a Game that involves interaction with a User interface to generate visual feedback on a video device. Computer vision is the science and technology of machines that see Image processing is any form of Signal processing for which the input is an image such as photographs or frames of video the output of image processing can be either an image Computational geometry is a branch of Computer science devoted to the study of algorithms which can be stated in terms of Geometry. Algorithmic topology, or computational topology, is a subfield of Topology with an overlap with areas of Computer science, in particular Computational

Industry

Industrial labs doing "blue sky" graphics research include:

• Adobe Advanced Technology Labs
• MERL
• Microsoft Research - Graphics
• NVIDIA Research

Major film studios notable for graphics research include:

• ILM
• PDI/Dreamworks Animation
• Pixar

Notable researchers in computer graphics

See also

Numerous sub-areas of computer graphics can be found in Category:3D computer graphics. James F Blinn is a computer scientist who first became widely known for his work as a computer graphics expert at NASA 's ' Bump mapping' is a Computer graphics technique where at each Pixel, a perturbation to the Surface normal of the object being rendered is Jack Elton Bresenham (born in 1937 was a professor of Computer science. A line drawing algorithm is a graphical Algorithm for approximating a line segment on discrete graphical media Loren C Carpenter (born 1947 is a Computer graphics researcher and developer Edwin Catmull, PhD (born 1945 in Parkersburg, West Virginia) is an Academy Award winning Computer scientist and current president of Walt Robert L Cook ( December 10 1952) is a Computer graphics researcher and developer and the co-creator of the RenderMan rendering Paul Debevec is a researcher in Computer graphics at the University of Southern California 's Institute for Creative Technologies. Ronald Paul "Ron" Fedkiw (FED-kew (born February 27 1968 is an Associate professor in the Stanford University department of Computer science James D Foley (born July 20, 1942) is Professor, Stephen Fleming Chair in Telecommunications and interim Dean of the College of Computing David Forsyth is an American computer scientist and full professor at the University of Illinois at Urbana-Champaign, born in South Africa Henry Fuchs is the Federico Gil Professor of Computer Science, Adjunct Professor of Biomedical Engineering, and Adjunct Professor of Radiation Oncology Pat Hanrahan is a Computer graphics researcher and professor of Computer Science and Electrical Engineering in the Computer Graphics Laboratory at Takeo Kanade (金出武雄 born 1945 in Hyogo Japan is a Japanese computer scientist and one of the world's foremost researchers in Computer vision. Jim Kajiya is a pioneer in the field of Computer graphics. He is perhaps best known for the development of the 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 Marc Levoy is a Computer graphics researcher and Professor of Computer Science and Electrical Engineering at Stanford University. James F O'Brien is a Computer graphics researcher and professor of Computer Science and Electrical Engineering at the University of California Berkeley Ken Perlin is a professor in the Department of Computer Science at New York University. Przemyslaw Prusinkiewicz is a Polish Computer scientist who advanced the idea that Fibonacci numbers in nature can be in part understood as the expression William Reeves, also known as Bill is a pioneer in the field of computer graphics James Albert Sethian is a professor of Mathematics at the University of California Berkeley, and the head of the Mathematics Group at the U The level set method (sometimes abbreviated as LSM) is a numerical technique for tracking interfaces and Shapes The advantage of the level set method is Greg Turk is an American-born researcher in the field of Computer graphics and an Associate Professor at Georgia Tech. Andries "Andy" van Dam (born 8 December 1938, Groningen) is a Dutch -born American professor of Computer science and former Lance J Williams is a prominent graphics researcher who made major contributions to texture map prefiltering shadow rendering algorithms facial animation and antialiasing techniques 3D computer graphics (in contrast to 2D computer graphics) are graphics that use a three-dimensional representation of geometric data that is stored in the computer 3D projection is any method of mapping three-dimensional points to a two-dimensional plane Cloth modeling is the term used for simulating cloth within a computer program usually in the realm of Computer graphics. Computer facial animation is primarily an area of Computer graphics that encapsulates models and techniques for generating and animating images of the human Head Digital geometry deals with discrete sets (usually discrete point sets considered to be digitized models or Images of objects of the Image editing encompasses the processes of altering Images whether they be digital photographs traditional analog photographs or Illustrations A geodesic dome is an almost spherical shell structure based on a network of Great circles ( Geodesics lying approximately on the surface of a Sphere Geometric manipulation of modeling primitives such as that performed by a Geometry Pipeline, is the first stage in Computer graphics systems which perform image generation based Geometry processing is a fast-growing area of Research that uses concepts from Applied mathematics, Computer science and Engineering to design The painter's algorithm, also known as a priority fill, is one of the simplest solutions to the Visibility problem in 3D computer graphics. SIGGRAPH (short for S pecial I nterest G roup on GRAPH ics and Interactive Techniques is the name of the annual conference on Computer graphics The Stanford Bunny is a Computer graphics test model developed by Greg Turk and Marc Levoy in 1994 at Stanford University. The Utah teapot or Newell teapot is a 3D model which has become a standard reference object (and something of an In-joke) in the Computer graphics A Video Display Controller or VDC is an Integrated circuit which is the main component in a Video signal generator, a device responsible for the production

References

External links

• A Critical History of Computer Graphics and Animation
• History of Computer Graphics series of articles