Alternate Frame Rendering (AFR) is a technique of graphics rendering in

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

s which combines the work output of two or more

graphics processing unit A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, m ...

s (GPU) for a single monitor, in order to improve image quality, or to accelerate the rendering performance. The technique is that one graphics processing unit computes all the ''odd'' video frames, the other renders the ''even'' frames. This technique is useful for generating 3D video sequences in real time, improving or filtering textured

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 to ...

s and performing other computationally intensive tasks, typically associated with

computer gaming A personal computer game, also known as a PC game or computer game, is a type of video game played on a personal computer (PC) rather than a video game console or arcade machine. Its defining characteristics include: more diverse and user-deter ...

CAD Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve co ...

and 3D modeling. One disadvantage of AFR is a defect known as micro stuttering.

Parallel rendering methods

AFR belongs to a class of parallel rendering methods, which subdivide a

four-dimensional A four-dimensional space (4D) is a mathematical extension of the concept of three-dimensional or 3D space. Three-dimensional space is the simplest possible abstraction of the observation that one only needs three numbers, called ''dimensions'', ...

image frame sequence (x,y,z and time) into smaller regions, each of which is then assigned to a different physical processor within a multi-processor array. Note that the regional boundaries may be defined in space or in time. Also, the multiple processors can be implemented within a single video card or separate video graphics cards can be combined, subject to the motherboard and I/O slot limitations. When separate video cards are used, they must be specifically designed to allow a "cross-link" between them. If a computer has two video cards that combine their outputs into a single video monitor, then one of four methods could be used to create the images. *Alternate Frame Rendering (AFR): One

(GPU) computes all the ''odd'' video frames, the other renders the ''even'' frames. (i.e. time division) *Split Frame Rendering (SFR): One GPU renders the ''top'' half of each video frame, the other does the ''bottom''. (i.e. plane division) * Checkerboard rendering: As the name implies, the image is split into smaller squares, which are assigned to different cards *

Scan-Line Interleave Scan-Line Interleave (SLI) from 3dfx is a method for linking two (or more) video cards or chips together to produce a single output. It is an application of parallel processing for computer graphics, meant to increase the processing power availa ...

: The origin of the SLI trademark, as employed by the 3dfx

Voodoo2 The Voodoo2 (or Voodoo2) is a set of three specialized 3D graphics chips on a single chipset setup, made by 3dfx. It was released in February 1998 as a replacement for the original Voodoo Graphics chipset. The card runs at a chipset clock rate o ...

, which renders a frame's even scan-lines on the first GPU and its odd scan-lines on the second. The SLI trademark passed to

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 ...

upon its acquisition of 3dfx in 2000 and now stands for

Scalable Link Interface Scalable Link Interface (SLI) is a brand name for a deprecated multi- GPU technology developed by Nvidia for linking two or more video cards together to produce a single output. SLI is a parallel processing algorithm for computer graphics, meant ...

References

{{reflist 3D rendering

Parallel rendering methods

See also

References