Geometric manipulation of modelling primitives, such as that performed by a geometry pipeline, is the first stage in

computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great deal ...

systems which perform image generation based on geometric models. While geometry pipelines were originally implemented in software, they have become highly amenable to hardware implementation, particularly since the advent of

very-large-scale integration Very large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit (Metal Oxide Semiconductor) ...

(VLSI) in the early 1980s. A device called the Geometry Engine developed by

Jim Clark James Clark Jr. OBE (4 March 1936 – 7 April 1968) was a British Formula One racing driver from Scotland, who won two World Championships, in 1963 and 1965. A versatile driver, he competed in sports cars, touring cars and in the Indianapol ...

and Marc Hannah at Stanford University in about 1981 was the watershed for what has since become an increasingly commoditized function in contemporary image-synthetic raster display systems.

Geometric transformation In mathematics, a geometric transformation is any bijection of a set to itself (or to another such set) with some salient geometrical underpinning. More specifically, it is a function whose domain and range are sets of points — most often ...

s are applied to the vertices of

polygon In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed '' polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two t ...

s, or other geometric objects used as modelling primitives, as part of the first stage in a classical geometry-based graphic image rendering pipeline. Geometric computations may also be applied to transform polygon or repair

surface normal In geometry, a normal is an object such as a line, ray, or vector that is perpendicular to a given object. For example, the normal line to a plane curve at a given point is the (infinite) line perpendicular to the tangent line to the curve ...

s, and then to perform the

lighting Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing dayli ...

and

shading Shading refers to the depiction of depth perception in 3D models (within the field of 3D computer graphics) or illustrations (in visual art) by varying the level of darkness. Shading tries to approximate local behavior of light on the object ...

computations used in their subsequent rendering.

History

Hardware implementations of the geometry pipeline were introduced in the early

Evans & Sutherland Evans & Sutherland is a pioneering American computer firm in the computer graphics field. Its current products are used in digital projection environments like planetariums. Its simulation business, which it sold to Rockwell Collins, sold product ...

Picture System, but perhaps received broader recognition when later applied in the broad range of graphics systems products introduced by

Silicon Graphics Silicon Graphics, Inc. (stylized as SiliconGraphics before 1999, later rebranded SGI, historically known as Silicon Graphics Computer Systems or SGCS) was an American high-performance computing manufacturer, producing computer hardware and soft ...

(SGI). Initially the SGI geometry hardware performed simple model space to

screen space This is a glossary of terms relating to computer graphics. For more general computer hardware terms, see glossary of computer hardware terms. 0–9 A B ...

viewing transformation In computer graphics, a computer graphics pipeline, rendering pipeline or simply graphics pipeline, is a conceptual model that describes what steps a graphics system needs to perform to render a 3D scene to a 2D screen. Once ...

s with all the lighting and shading handled by a separate hardware implementation stage. In later, much higher performance applications, such as the RealityEngine, they began to be applied to perform part of the rendering support as well. More recently, perhaps dating from the late 1990s, the hardware support required to perform the manipulation and rendering of quite complex scenes has become accessible to the consumer market. Companies such as

Nvidia Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as VIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as VIDIA with a large italicized lowercase "n" on products from the mid 1990s to ...

and

AMD Graphics Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufact ...

(formerly ATI) are two current leading representatives of hardware vendors in this space. The

GeForce GeForce is a brand A brand is a name, term, design, symbol or any other feature that distinguishes one seller's good or service from those of other sellers. Brands are used in business, marketing, and advertising for recognition and, ...

line of

graphics card A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer mo ...

s from Nvidia was the first to support full

OpenGL OpenGL (Open Graphics Library) is a cross-language, cross-platform application programming interface (API) for rendering 2D and 3D vector graphics. The API is typically used to interact with a graphics processing unit (GPU), to achieve ha ...

and

Direct3D Direct3D is a graphics application programming interface (API) for Microsoft Windows. Part of DirectX, Direct3D is used to render three-dimensional graphics in applications where performance is important, such as games. Direct3D uses hardware ...

hardware geometry processing in the consumer PC market, while some earlier products such as Rendition Verite incorporated hardware geometry processing through proprietary programming interfaces. On the whole, earlier graphics accelerators by

3Dfx 3dfx Interactive was an American technology company headquartered in San Jose, California, founded in 1994, that specialized in the manufacturing of 3D graphics processing units, and later, video cards. It was a pioneer in the field from the ...

Matrox Matrox Graphics, Inc. is a producer of video card components and equipment for personal computers and workstations. Based in Dorval, Quebec, Canada, it was founded in 1976 by Lorne Trottier and Branko Matić. The name is derived from "Ma" in ...

and others relied on the

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...

for geometry processing. This subject matter is part of the technical foundation for modern computer graphics, and is a comprehensive topic taught at both the undergraduate and graduate levels as part of a

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to practical disciplines (includin ...

education.

References

{{Graphics Processing Unit 3D computer graphics

History

See also

References