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DXTn
S3 Texture Compression (S3TC) (sometimes also called DXTn, DXTC, or BCn) is a group of related lossy texture compression algorithms originally developed by Iourcha et al. of S3 Graphics, Ltd. for use in their Savage 3D computer graphics accelerator. The method of compression is strikingly similar to the previously published Color Cell Compression, which is in turn an adaptation of Block Truncation Coding published in the late 1970s. Unlike some image compression algorithms (e.g. JPEG), S3TC's fixed-rate data compression coupled with the single memory access (cf. Color Cell Compression and some VQ-based schemes) made it well-suited for use in compressing textures in hardware-accelerated 3D computer graphics. Its subsequent inclusion in Microsoft's DirectX 6.0 and OpenGL 1.3 (via the GL_EXT_texture_compression_s3tc extension) led to widespread adoption of the technology among hardware and software makers. While S3 Graphics is no longer a competitor in the graphics accelerato ...
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Texture Mapping
Texture mapping is a method for mapping a texture on a computer-generated graphic. Texture here can be high frequency detail, surface texture, or color. History The original technique was pioneered by Edwin Catmull in 1974. Texture mapping originally referred to diffuse mapping, a method that simply mapped pixels from a texture to a 3D surface ("wrapping" the image around the object). In recent decades, the advent of multi-pass rendering, multitexturing, mipmaps, and more complex mappings such as height mapping, bump mapping, normal mapping, displacement mapping, reflection mapping, specular mapping, occlusion mapping, and many other variations on the technique (controlled by a materials system) have made it possible to simulate near-photorealism in real time by vastly reducing the number of polygons and lighting calculations needed to construct a realistic and functional 3D scene. Texture maps A is an image applied (mapped) to the surface of a shape or polygon. This ...
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Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression al ...
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Open-source Software
Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2008 report by the Standish Group stated that adoption of open-source software models has resulted in savings of about $60 billion per year for consumers. Open source code can be used for studying and allows capable end users to adapt software to their personal needs in a similar way user scripts an ...
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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 early-mid 2000s. Though unofficial, second letter capitalization of NVIDIA, i.e. nVidia, may be found within enthusiast communities and publications. ( ) is an American multinational technology company incorporated in Delaware and based in Santa Clara, California. It is a software and fabless company which designs graphics processing units (GPUs), application programming interface (APIs) for data science and high-performance computing as well as system on a chip units (SoCs) for the mobile computing and automotive market. Nvidia is a global leader in artificial intelligence hardware and software. Its professional line of GPUs are used in workstations for applications in such fields as architecture, engineering and construction, media ...
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Pixel Shader
In computer graphics, a shader is a computer program that calculates the appropriate levels of light, darkness, and color during the rendering of a 3D scene - a process known as ''shading''. Shaders have evolved to perform a variety of specialized functions in computer graphics special effects and video post-processing, as well as general-purpose computing on graphics processing units. Traditional shaders calculate rendering effects on graphics hardware with a high degree of flexibility. Most shaders are coded for (and run on) a graphics processing unit (GPU), though this is not a strict requirement. ''Shading languages'' are used to program the GPU's rendering pipeline, which has mostly superseded the fixed-function pipeline of the past that only allowed for common geometry transforming and pixel-shading functions; with shaders, customized effects can be used. The position and color (hue, saturation, brightness, and contrast) of all pixels, vertices, and/or textures us ...
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Doom 3
''Doom 3'' is a 2004 survival horror first-person shooter video game developed by id Software and published by Activision. ''Doom 3'' was originally released for Microsoft Windows on August 3, 2004, adapted for Linux later that year, and ported by Aspyr Media for Mac OS X in 2005. Developer Vicarious Visions ported the game to the Xbox, releasing it on April 3, 2005. ''Doom 3'' is set on Mars in 2145, where a military-industrial conglomerate has set up a scientific research facility into fields such as teleportation, biological research, and advanced weapons design. The teleportation experiments open a gateway to Hell, resulting in a catastrophic invasion of the Mars base by demons. The player controls a space marine who fights through the base to stop the demons attacking Mars and reaching Earth. ''Doom 3'' is the first reboot of the ''Doom'' series, ignoring the events of the previous games. ''Doom 3'' utilizes the id Tech 4 game engine, which has since been licensed out to ...
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Id Software
id Software LLC () is an American video game developer based in Richardson, Texas. It was founded on February 1, 1991, by four members of the computer company Softdisk: programmers John Carmack and John Romero, game designer Tom Hall, and artist Adrian Carmack. id Software made important technological developments in video game technologies for the PC (running MS-DOS and Windows), including work done for the '' Wolfenstein'', ''Doom'', and '' Quake'' franchises. id's work was particularly important in 3D computer graphics technology and in game engines that are used throughout the video game industry. The company was involved in the creation of the first-person shooter (FPS) genre: ''Wolfenstein 3D'' is often considered to be the first true FPS; ''Doom'' is a game that popularized the genre and PC gaming in general; and '' Quake'' was id's first true 3D FPS. On June 24, 2009, ZeniMax Media acquired the company. In 2015, they opened a second studio in Frankfurt, Germany. ...
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ATI Technologies
ATI Technologies Inc. (commonly called ATI) was a Canadian semiconductor industry, semiconductor technology corporation based in Markham, Ontario, Markham, Ontario, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technology Inc., the company listed publicly in 1993. Advanced Micro Devices (AMD) acquired ATI in 2006. As a major fabrication-less or fabless semiconductor company, ATI conducted research and development in-house and outsourcing, outsourced the manufacturing and assembly of its products. With the decline and eventual bankruptcy of 3dfx in 2000, ATI and its chief rival Nvidia emerged as the two dominant players in the graphics processors industry, eventually forcing other manufacturers into niche roles. The acquisition of ATI in 2006 was important to AMD's strategic development of its AMD Fusion, Fusion generation of computer processors, which integrated general processing abilities with graphics processing function ...
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Compression Artifacts
A compression artifact (or artefact) is a noticeable distortion of media (including images, audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the media's data so that it becomes small enough to be stored within the desired disk space or transmitted (''streamed'') within the available bandwidth (known as the data rate or bit rate). If the compressor cannot store enough data in the compressed version, the result is a loss of quality, or introduction of artifacts. The compression algorithm may not be intelligent enough to discriminate between distortions of little subjective importance and those objectionable to the user. The most common digital compression artifacts are DCT blocks, caused by the discrete cosine transform (DCT) compression algorithm used in many digital media standards, such as JPEG, MP3, and MPEG video file formats. These compression artifacts appear when heavy compression is applied, and occu ...
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Normal Mapping
In 3D computer graphics, normal mapping, or Dot3 bump mapping, is a texture mapping technique used for faking the lighting of bumps and dents – an implementation of bump mapping. It is used to add details without using more polygons. A common use of this technique is to greatly enhance the appearance and details of a low polygon model by generating a normal map from a high polygon model or height map. Normal maps are commonly stored as regular RGB images where the RGB components correspond to the X, Y, and Z coordinates, respectively, of the surface normal. History In 1978 Jim Blinn described how the normals of a surface could be perturbed to make geometrically flat faces have a detailed appearance. The idea of taking geometric details from a high polygon model was introduced in "Fitting Smooth Surfaces to Dense Polygon Meshes" by Krishnamurthy and Levoy, Proc. SIGGRAPH 1996, where this approach was used for creating displacement maps over nurbs. In 1998, two papers were pre ...
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Lossy Data Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to Lossless compression, lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely use ...
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RGBA Color Space
RGBA stands for red green blue alpha. While it is sometimes described as a color space, it is actually a three-channel RGB color model supplemented with a fourth ''alpha channel''. Alpha indicates how opaque each pixel is and allows an image to be combined over others using alpha compositing, with transparent areas and anti-aliasing of the edges of opaque regions. The term does ''not'' define what RGB color space is being used. It also does not state whether or not the colors are premultiplied by the alpha value, and if they are it does not state what color space that premultiplication was done in. This means more information than just "RGBA" is needed to determine how to handle an image. In some contexts the abbreviation "RGBA" means a specific memory layout (called RGBA8888 below), with other terms such as "BGRA" used for alternatives. In other contexts "RGBA" means any layout. Representation In computer graphics, pixels encoding the RGBA color space information must be ...
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