View source for Glossary of computer graphics

{{Short description|none}}
{{Use dmy dates|date=August 2023}}
{{more citations needed|date=June 2016}}
This is a glossary of terms relating to [[computer graphics]].

For more general computer hardware terms, see [[glossary of computer hardware terms]].

{{Compact ToC|num=yes|refs=yes}}

== 0–9 ==
{{glossary}}
{{term|[[Kernel (image processing)|2D convolution]]}}
{{defn|Operation that applies linear filtering to image with a given two-dimensional kernel, able to achieve e.g. edge detection, blurring, etc.}}

{{term|2D image}}

{{term|2D texture map}}
{{defn|A [[texture map]] with [[two-dimensional space|two dimensions]], typically indexed by [[#UV coordinates|UV coordinates]].}}

{{term|2D vector}}
{{defn|A [[two-dimensional space|two-dimensional]] [[vector (mathematics)|vector]], a common [[data type]] in [[rasterization]] algorithms, [[2D computer graphics]], [[graphical user interface]] libraries.}}

{{term|2.5D|content=[[2.5D]]}}
{{defn|Also pseudo 3D. Rendering whose result looks 3D while actually not being 3D or having great limitations, e.g. in camera degrees of freedom.}}

{{term|3D graphics pipeline}}
{{defn|A [[graphics pipeline]] taking [[3D model]]s and producing a 2D [[bitmap image]] result.}}

{{term|3D paint tool}}
{{defn|A [[3D graphics application]] for [[digital painting]] of multiple [[texture map]] image channels directly onto a rotated [[3D model]], such as [[zbrush]] or [[mudbox]], also sometimes able to modify vertex attributes.}}

{{term|3D scene}}
{{defn|A collection of [[3D model]]s and [[lightsource]]s in world space, into which a camera may be placed, describing a scene for [[3D rendering]].}}

{{term|3D unit vector}}
{{defn|A [[unit vector]] in [[3D space]].}}

{{term|[[4D vector]]}}
{{defn|A common [[datatype]] in graphics code, holding [[homogeneous coordinates]] or [[#RGBA|RGBA]] data, or simply a [[3D vector]] with unused W to benefit from alignment, naturally handled by machines with 4-element [[SIMD]] registers.}}

{{term|4×4 matrix}}
{{defn|A [[matrix (mathematics)|matrix]] commonly used as a [[transformation matrix|transformation]] of [[homogeneous coordinates]] in [[3D graphics pipelines]].<ref>{{Cite web|url=http://web.cs.wpi.edu/~emmanuel/courses/cs543/slides/lecture04_p1.pdf|title=matrices for computer graphics|accessdate=6 August 2023}}</ref>
}}

{{term|7e3 format}}
{{defn|A packed pixel format supported by some [[graphics processing unit]]s (GPUs) where a single [[32-bit word]] encodes three 10-bit [[floating-point arithmetic|floating-point]] color channels, each with seven bits of [[Floating-point#mantissa|mantissa]] and three bits of [[floating-point#Exponent|exponent]].<ref>{{Cite web|url=http://fileadmin.cs.lth.se/cs/Personal/Michael_Doggett/talks/x05-xenos-doggett.pdf|title=xbox360}}</ref>
}}

{{end glossary}}

== A ==
{{glossary}}
{{term|AABB}}
{{defn|[[Axis-aligned bounding box]] (sometimes called "axis oriented"), a [[bounding box]] stored in world coordinates; one of the simplest [[bounding volume]]s.}}

{{term|Additive blending}}
{{defn|A [[blend modes|compositing operation]] where <math>dst=dst+src,</math> without the use of an [[alpha compositing|alpha channel]], used for various effects. Also known as ''[[linear dodge]]'' in some applications.}}

{{term|Affine texture mapping|content=[[Affine texture mapping]]}}
{{defn|Linear interpolation of texture coordinates in screen space without taking perspective into account, causing texture distortion.}}

{{term|Aliasing|content=[[Aliasing]]}}
{{defn|Unwanted effect arising when sampling high-frequency signals, in computer graphics appearing e.g. when downscaling images. Antialiasing methods can prevent it.}}

{{anchor|[[Alpha channel]]}}
{{term|Alpha channel|content=[[Alpha channel]]}}
{{defn|An additional image channel (e.g. extending an RGB image) or standalone channel controlling [[alpha blending]].}}

{{term|Ambient light|content=[[Shading#Ambient lighting|Ambient lighting]]}}
{{defn|An approximation to the light entering a region from a wide range of directions, used to avoid needing an exact solution to the [[rendering equation]].}}

{{term|[[Ambient occlusion]] (AO)}}
{{defn|Effect approximating, in an inexpensive way, one aspect of [[global illumination]] by taking into account how much ambient light is blocked by nearby geometry, adding visual clues about the shape.<ref name="akenine" />{{rp|446}}}}

{{term|Analytic model}}
{{defn|A [[mathematical model]] for a phenomenon to be [[simulated]], e.g. some approximation to [[#shading calculation|surface shading]]. Contrasts with [[Empirical model]]s based purely on recorded data.}}

{{term|Anisotropic filtering|content=[[Anisotropic filtering]]}}
{{defn|Advanced texture filtering improving on [[mipmap]]ping, preventing aliasing while reducing blur in textured polygons at oblique angles to the camera.}}

{{term|Anti-aliasing|content=[[Spatial anti-aliasing|Anti-aliasing]]}}
{{defn|Methods for filtering and sampling to avoid [[visual artifact]]s associated with the uniform [[pixel]] grid in [[3D rendering]].}}

{{term|Array texture}}
{{defn|A form of [[texture map]] containing an [[array data structure|array]] of 2D texture slices selectable by a 3rd 'W' [[texture coordinate]]; used to reduce state changes in [[3D rendering]].<ref>{{Cite web|url=https://learn.microsoft.com/en-us/windows/win32/direct3d11/overviews-direct3d-11-resources-textures-intro|title=Introduction To Textures in Direct3D 11 - Win32 apps|date=August 23, 2019|website=learn.microsoft.com}}</ref>
}}

{{term|[[Augmented reality]]}}
{{defn|Computer-rendered content inserted into the user's view of the real world.<ref name="akenine" />{{rp|917}}}}

{{term|AZDO}}
{{defn|Approaching zero driver overhead, a set of techniques aimed at reducing the [[Central processing unit|CPU]] overhead in preparing and submitting rendering commands in the [[OpenGL]] pipeline. A compromise between the traditional GL API and other high-performance low-level rendering APIs.<ref>{{Cite web|url=https://www.khronos.org/assets/uploads/developers/library/2014-gdc/Khronos-OpenGL-Efficiency-GDC-Mar14.pdf|title=AZDO|accessdate=6 August 2023}}</ref>
}}

{{end glossary}}

== B ==
{{glossary}}
{{term|Backface culling|content=[[Back-face culling]]}}
{{defn|Culling (discarding) of polygons that are facing backwards from the camera.}}

{{term|[[Texture mapping#Baking|Baking]]}}
{{defn|Performing an expensive calculation offline, and caching the results in a [[texture map]] or vertex attributes. Typically used for generating [[lightmap]]s, [[normal mapping|normal maps]], or low [[level of detail (computer graphics)|level of detail]] models.<ref>{{Cite web|url=https://wiki.blender.org/index.php/Doc:2.4/Manual/Render/Bake|title=blender manual – baking|accessdate=6 August 2023|archive-date=27 November 2015|archive-url=https://web.archive.org/web/20151127191955/http://wiki.blender.org/index.php/Doc:2.4/Manual/Render/Bake|url-status=dead}}</ref>}}

{{term|[[Barycentric coordinate system|Barycentric coordinates]]}}
{{defn|Three-element coordinates of a point inside a triangle.}}

{{term|[[Beam tracing]]}}
{{defn|Modification of [[ray tracing (graphics)|ray tracing]] which instead of lines uses pyramid-shaped beams to address some of the shortcomings of traditional ray tracing, such as aliasing.<ref>{{cite book |last1=Heckbert |first1=Paul |last2=Hanrahan |first2=Pat |title=Proceedings of the 11th annual conference on Computer graphics and interactive techniques - SIGGRAPH '84 |chapter=Beam Tracing Polygonal Objects |date=1984 |pages=119–127 |doi=10.1145/800031.808588 |isbn=0897911385 |s2cid=2845686 }}</ref>}}

{{term|Bicubic filtering|content=[[Bicubic interpolation]]}}
{{defn|Extension of [[cubic interpolation]] to 2D, commonly used when scaling textures.}}

{{term|Bilinear filtering|content=[[Bilinear interpolation]]}}
{{defn|[[Linear interpolation]] extended to 2D, commonly used when scaling textures.}}

{{term|Binding}}
{{defn|Selecting a resource (texture, buffer, etc.) to be referenced by future commands.}}

{{term|Billboard}}
{{defn|A textured rectangle that keeps itself oriented towards the camera, typically used e.g. for vegetation or particle effects.<ref name="akenine" />{{rp|551}}}}

{{term|[[Binary space partitioning]] (BSP)}}
{{defn|A data structure that can be used to accelerate visibility determination, used e.g. in [[Doom engine]].}}

{{term|Bit depth}}
{{defn|The number of [[bits per pixel]], sample, or [[texel (graphics)|texel]] in a [[bitmap image]] (holding one or more image channels, typical values being 4,&nbsp;8,&nbsp;16,&nbsp;24,&nbsp;32)}}

{{term|Bitmap|content=[[Bitmap]]}}
{{defn|Image stored by pixels.}}

{{term|Bit plane|content=[[Bit plane]]}}
{{defn|A format for [[bitmap image]]s storing [[monochrome|1 bit per pixel]] in a contiguous [[Two-dimensional array|2D array]]; Several such [[parallel array]]s combine to produce the a higher-[[#bit depth|bit-depth]] image. Opposite of packed-pixel format.}}

{{term|Blend operation}}
{{defn|A render state controlling [[alpha blending]], describing a formula for combining source and destination [[pixel]]s.}}

{{term|Bone}}
{{defn|Coordinate systems used to control surface deformation (via Weight maps) during [[skeletal animation]]. Typically stored in a [[hierarchy]], controlled by [[key frame]]s, and other procedural [[constraint (skeletal animation)|constraints]].}}

{{term|Bounding box|content=[[Bounding volume#bounding box|Bounding box]]}}
{{defn|One of the simplest type of [[bounding volume]], consisting of [[axis-aligned bounding box|axis-aligned]] or [[Object-oriented bounding box|object-aligned]] [[extent (computer graphics)|extent]]s.}}

{{term|Bounding volume|content=[[Bounding volume]]}}
{{defn|A mathematically simple volume, such as a sphere or a box, containing 3D objects, used to simplify and accelerate spatial tests (e.g. for visibility or collisions).<ref name="akenine" />{{rp|819}}}}

{{term|BRDF}}
{{defn|[[Bidirectional reflectance distribution function]]s (BRDFs), [[empirical model]]s defining 4D functions for [[#shading calculation|surface shading]] indexed by a view vector and light vector relative to a surface.<ref name='nicodemus_1965'>
{{Cite journal
| volume = 4
| issue = 7
| pages = 767–775
| last = Nicodemus
| first = Fred
| title = Directional reflectance and emissivity of an opaque surface
| journal = Applied Optics
| doi = 10.1364/AO.4.000767
| year = 1965
|bibcode = 1965ApOpt...4..767N }}</ref>
}}

{{term|[[Bump mapping]]}}
{{defn|Technique similar to normal mapping that instead of normal maps uses so called bump maps (height maps).}}

{{term|BVH}}
{{defn|[[Bounding volume hierarchy]] is a tree structure on a set of geometric objects.}}

{{end glossary}}

== C ==
{{glossary}}
{{term|Camera}}
{{defn|A [[virtual camera]] from which [[rendering (computer graphics)|rendering]] is performed, also sometimes referred to as 'eye'.}}

{{term|Camera space}}
{{defn|A space with the [[#camera|camera]] at the [[Origin (geometry)|origin]], aligned with the viewer's direction, after the application of the [[world transformation]] and view transformation.}}

{{term|Cel shading|content=[[Cel shading]]}}
{{defn|Cartoon-like shading effect.}}

{{term|[[Clipping (computer graphics)|Clipping]]}}
{{defn|Limiting specific operations to a specific region, usually the view frustum.}}

{{term|Clipping plane}}
{{defn|A [[Plane (geometry)|plane]] used to [[clipping (computer graphics)|clip]] [[rendering primitive]]s in a [[graphics pipeline]]. These may define the [[viewing frustum|view frustum]] or be used for other effects.}}

{{term|Clip space|content=[[Clip space]]}}
{{defn|Coordinate space in which clipping is performed.}}

{{term|Clip window}}
{{defn|A rectangular region in screen space, used during [[clipping (computer graphics)|clipping]]. A clip window may be used to enclose a region around a [[#portal|portal]] in [[portal rendering]].}}

{{term|CLUT|content=[[Color look-up table|CLUT]]}}
{{defn|A table of RGB color values to be indexed by a lower-[[bits per pixel|bit-depth]] image (typically 4–8&nbsp;bits), a form of [[vector quantization]].}}

{{term|[[Color bleeding (computer graphics)|Color bleeding]]}}
{{defn|Unwanted effect in texture mapping. A color from a border of unmapped region of the texture may appear (bleed) in the mapped result due to interpolation.}}

{{term|Color channels}}
{{defn|The set of [[Channel (digital image)|channels]] in a [[bitmap image]] representing the visible color components, i.e. distinct from the alpha channel or other information.}}

{{term|Color resolution|content=[[Color depth|Color resolution]]}}

{{term|Command buffer}}
{{defn|A region of [[Memory (computing)|memory]] holding a set of instructions for a [[graphics processing unit]] for rendering a scene or portion of a scene. These may be generated manually in [[bare metal]] programming, or managed by low level [[List of rendering APIs|rendering APIs]], or handled internally by [[List of rendering APIs|high level rendering APIs]].}}

{{term|Command list}}
{{defn|A group of rendering commands ready for submission to a [[graphics processing unit]], see also Command buffer.}}

{{term|Compute API}}
{{defn|An [[API]] for efficiently processing large amounts of data.<ref>{{cite book|last1=Cozzi|first1=Patrick|last2=Riccio|first2=Christophe|title=OpenGL Insights|date=2012|publisher=CRC Press|location=United States|isbn=9781439893760|page=133|url=https://books.google.com/books?id=CCVenzOGjpcC&q=compute+API&pg=PA133|access-date=27 August 2016|language=en}}</ref>}}

{{term|Compute shader}}
{{defn|A [[compute kernel]] managed by a rendering API, with easy access to rendering resources.}}

{{term|[[Cone tracing]]}}
{{defn|Modification of [[Ray tracing (graphics)|ray tracing]] which instead of lines uses cones as rays in order to achieve e.g. [[antialiasing]] or soft shadows.<ref>{{cite journal |last1=Amanatides |first1=John |journal=ACM SIGGRAPH Computer Graphics |title=Ray tracing with cones |date=January 1984 |volume=18 |issue=3 |pages=129–135 |doi=10.1145/964965.808589 }}</ref>}}

{{term|Connectivity information}}
{{defn|Indices defining [rendering primitive]s between [[Vertex (computer graphics)|vertices]], possibly held in index buffers. describes geometry as a [[graph (discrete mathematics)|graph]] or [[hypergraph]].}}

{{term|CSG}}
{{defn|[[Constructive solid geometry]], a method for generating complex [[solid model]]s from [[boolean function|boolean operations]] combining simpler modelling primitives.}}

{{term|Cube mapping|content=[[Cube mapping]]}}
{{defn|A form of environment reflection mapping in which the environment is captured on a surface of a cube (cube map).}}

{{term|[[Hidden-surface determination|Culling]]}}
{{defn|Before rendering begins, culling removes objects that don't significantly contribute to the rendered result (e.g. being obscured or outside camera view).<ref name="akenine" />{{rp|830}}}}

{{end glossary}}

== D ==
{{glossary}}

{{term|Decal}}
{{defn|A "sticker" picture applied onto a surface (e.g. a crack on the wall).<ref name="akenine" />{{rp|888}}}}

{{term|Detail texture}}
{{defn|[[Texture map]]s repeated at high frequency combined with a ''main texture'' on a surface to prevent a blurred appearance close to the camera.}}

{{term|Deferred rendering|content=[[Deferred shading]]}}
{{defn|A technique by which computation of shading is deferred to later stage by rendering in two passes, potentially increasing performance by not discarding expensively shaded pixels. The first pass only captures surface parameters (such as depth, normals and material parameters), the second one performs the actual shading and computes the final colors.<ref name="akenine" />{{rp|884}}}}

{{term|Deformation lattice}}
{{defn|A means of controlling [[free-form deformation]] via a regular [[3D grid]] of [[control points (mathematics)|control points]] moved to arbitrary positions, with polynomial interpolation of the space between them.}}

{{term|Degenerate triangles}}
{{defn|Zero area triangle primitives placed in a [[triangle strip]] between actual primitives, to allow many parts of a [[triangle mesh]] to be rendered in a single drawcall. These are rejected by the triangle setup unit.<ref>{{cite web|title=sgi tristrip joining with degenerates|url=ftp://ftp.sgi.com/opengl/contrib/blythe/advanced99/notes/node18.html}}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
}}

{{term|Delaunay triangulation|content=[[Delaunay triangulation]]}}
{{defn|A method for generating an efficient triangulating between a set of [[Vertex (computer graphics)|vertices]] in a [[Plane (geometry)|plane]].}}

{{term|Depth buffer}}
{{defn|A [[bitmap image]] holding depth values (either a [[Z buffer]] or a [[#W buffer|W buffer]]), used for [[visible surface determination]], during [[rasterization]] of 3D scenes}}

{{term|Depth map|content=[[Depth map]]}}
{{defn|A [[bitmap image]] or [[texture map]] holding depth values. Similar to a [[height map]] or [[displacement map]], but usually associated with a projection.}}

{{term|Depth value}}
{{defn|A value in a [[depth map]] representing a distance perpendicular to the space of an image.}}

{{term|Diffuse light|content=[[Diffuse lighting]]}}
{{defn|In shading, a diffuse component of light is the light reflected from the surface uniformly into all directions. This component depends on the surface normal and direction to the light source but not on the viewer's position.}}

{{term|[[Direct3D]]}}
{{defn|[[Microsoft Windows]] 3D API, with similar architecture to [[OpenGL]].}}

{{term|Displacement mapping|content=[[Displacement mapping]]}}
{{defn|a method for adding detail to surfaces by [[subdivision (computer graphics)|subdivision]] and displacement of the resulting [[Vertex (computer graphics)|vertices]] from a [[height map]].<ref>{{cite web|title = gpu gems displacement mapping|url = http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter08.html|access-date = 7 June 2016|archive-date = 25 May 2016|archive-url = https://web.archive.org/web/20160525122702/http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter08.html|url-status = dead}}</ref>
}}

{{term|[[Distributed ray tracing]]}}
{{defn|Modification of [[Ray tracing (graphics)|ray tracing]] that casts multiple rays through each pixel in order to model soft phenomena such as soft shadows, depth of field etc.}}

{{term|[[Double buffer]]ing}}
{{defn|Using a dedicated buffer for rendering and copying the result to the screen buffer when finished. This prevents stutter on the screen and the user seeing rendering in progress.}}

{{term|Drawcall}}
{{defn|A single rendering command submitted to a rendering API, referring to a single set of render states.}}

{{end glossary}}

== E ==
{{glossary}}

{{term|Edge vector}}
{{defn|A [[vector (mathematics and physics)|vector]] between 2 position [[Vertex (computer graphics)|vertices]] in a [[polygon]] or [[polygon mesh]], along an [[Edge (geometry)|edge]].}}

{{term|[[Reflection mapping|Environment mapping]]}}
{{defn|Also reflection mapping, a technique of approximating reflections of environment on complex surfaces of [[3D modeling|3D models]] in real time. A complete 360 degree view of environment needs to be prerendered and stored in a texture using a specific mapping (e.g. [[cube mapping]], [[sphere mapping]] etc.)}}

{{term|Extents}}
{{defn|The minimum and maximum values of an object or [[Geometric primitive|primitive]] along a [[coordinate axis]] or set of axes.}}

{{end glossary}}

== F ==
{{glossary}}

{{term|Fixed-function pipeline}}
{{defn|A hardware [[rendering pipeline]] without [[shader]]s, composed entirely of [[fixed-function unit]]s. A limited number of functions may be controlled by render states.}}

{{term|Fixed-function unit}}
{{defn|A piece of hardware in a [[graphics processing unit]] implementing a specific function (such as triangle setup or texture sampling), without programmable control by [[shaders]].}}

{{term|[[Flat shading]]}}
{{defn|Shading that assigns a uniform color to each face of a 3D model, giving it a "sharp-edge" look.}}

{{term|Forward rendering}}
{{defn|A term for traditional [[3D rendering pipeline]]s which sort [[lightsource]]s applicable to [[3D modeling|3D models]] in world space prior to [[rasterization]]. Contrasts with [[Deferred shading]].}}

{{term|Forward-plus rendering}}
{{defn|An extension of forward rendering using [[compute shader]]s to place [[lightsource]]s into screen space tiles, to accelerate the use of many [[lightsource]]s, bypassing some of the disadvantages of [[deferred shading]].<ref>{{Cite web|url=https://www.3dgep.com/forward-plus/|title=Forward+ Rendering|date=September 4, 2015}}</ref>
}}

{{term|[[Fractal]]}}
{{defn|A complex, self-similar shape described by a simple equation. Fractals can be used e.g. in procedural terrain generation.{{citation needed|date=April 2020}}}}

{{term|Fragment (pixel) shader}}
{{defn|Shader processing individual pixels or fragments (values that may potentially become pixels).}}

{{term|[[Frustum culling]]}}
{{defn|A stage in a [[rendering pipeline]], filtering out [[3D models]] whose [[bounding volume]]s fail an intersection test with the [[view frustum]], allowing trivial rejection.}}

{{term|Fresnel}}
{{defn|According to [[Fresnel equations]], surfaces show more specular reflections when viewed at near-grazing incidence. This effect is often simulated in computer graphics.}}

{{term|FXAA|content=[[Fast approximate anti-aliasing|FXAA]]}}
{{defn|An approximate [[antialiasing]] method performed in a [[#post processing|post-processing]] step which smooths the image in screen space, guided by [[edge detection]] (contrasting with the usual [[supersampling]] approaches that require larger frame-buffers).}}

{{end glossary}}

== G ==
{{glossary}}

{{term|Geometry}}
{{defn|Typically used to refer to [[Vertex (computer graphics)|vertex]] & rendering primitive [[#connectivity information|connectivity information]] (distinct from [[Materials system|materials]] and [[texture map|textures]]).<ref name="akenine" />{{rp|47}}}}

{{term|Geometry shader}}
{{defn|In APIs such as [[OpenGL]] and [[Direct3D]], geometry shader is an optional stage able to process 3D model geometry in more advanced ways than a vertex or tessellation shaders (e.g. turn primitives into other primitives).}}

{{term|G-buffer}}
{{defn|A screen space representation of geometry and [[Materials system|material]] information, generated by an intermediate rendering pass in [[deferred shading]] [[rendering pipeline]]s.<ref>{{Cite web|url=https://learnopengl.com/|title=Learn OpenGL, extensive tutorial resource for learning Modern OpenGL|website=learnopengl.com}}</ref>
}}

{{term|Global illumination|content=[[Global illumination]]}}
{{defn|Computing the global interactions of light within the scene, e.g. reflections of light from one object to another, by which realism is added.}}

{{term|[[Gouraud shading]]}}
{{defn|Shading technique that computes values at triangle vertices and interpolates them across the surface. This is more realistic and computationally expensive than flat shading, and less than Phong shading.}}

{{term|GPU|content=[[Graphics processing unit]]}}
{{defn|[[Computer hardware|Hardware]] used to accelerate graphical computations.}}

{{term|Graphical shader}}
{{defn|A [[shader]] associated with the [[rendering pipeline]]; not a [[compute shader]].}}

{{term|Grid cell index}}
{{defn|[[Integer]] [[coordinates]] in a [[multidimensional array]].}}

{{end glossary}}

== H ==
{{glossary}}

{{term|HDR}}
{{defn|[[High-dynamic-range imaging]], an [[#image format|image format]] using [[floating-point arithmetic|floating-point]] values. Allows additional realism with [[post processing (images)|post processing]].}}

{{term|Heightmap|content=[[Heightmap]]}}
{{defn|A [[2D array]] or [[texture map]] holding height values; typically used for defining landscapes, or for [[displacement mapping]]}}

{{term|Homogenous coordinates|content=[[Homogeneous coordinates]]}}
{{defn|Coordinates of form ''(x,y,z,w)'' used during matrix transforms of vertices, allowing to perform non-linear transforms such as the [[perspective transform]].}}

{{end glossary}}

== I ==
{{glossary}}

{{term|Image channel}}
{{defn|A single component (referred to as a [[channel (digital image)|channel]]) of a [[bitmap image]]; one of multiple components per [[pixel]], e.g. for [[RGB color space|RGB]] or [[YUV color space]], or additional channels for [[alpha blending]]}}

{{term|Image format}}
{{defn|A specific way of representing a [[bitmap image]] in [[memory (computing)|memory]], also refers to [[image file format]]s.}}

{{term|Image generation}}
{{defn|Synonymous with [[Rendering (computer graphics)|rendering]]; taking a 3D scene (or other form of encoded data) and producing a [[bitmap image]] result.}}

{{term|Image generator}}
{{defn|A [[hardware accelerator]] for image generation, almost synonymous with a [[graphics processing unit]], but historically used to refer to devices aimed at [[realtime rendering]] for [[simulation]] (e.g. [[Evans & Sutherland]] ESIG line).}}

{{term|[[Image and object order rendering|Image order rendering]]}}
{{defn|Rendering methods that iterate over pixels of the screen in order to draw the image (e.g. [[ray tracing (graphics)|raytracing]]).}}

{{term|[[Image plane]]}}
{{defn|The plane in the world which is identified with the plane of the display monitor used to view the image that is being rendered.}}

{{term|Immediate mode|content=[[Immediate mode (computer graphics)|Immediate mode rendering]]}}
{{defn|The submission of rendering commands and rendering primitive data without the extensive use of managed resources; rendering primitive vertex attribute data may be embedded directly into a command list, rather than referenced [[indirection (computing)|indirectly]] from resources.}}

{{term|Impostor}}
{{defn|A dynamically rendered [[Billboard (computer graphics)|Billboard]] [[texture map]] used to stand in for geometry in the distance. A form of [[Level of detail (computer graphics)|level of detail]] optimization.<ref>{{Cite web|url=https://developer.nvidia.com/gpugems/gpugems3/part-iv-image-effects/chapter-21-true-impostors|title=Chapter 21. True Impostors|website=NVIDIA Developer}}</ref>
}}

{{term|Incremental error algorithm}}
{{defn|A set of [[rasterization algorithm]]s which use simple [[integer arithmetic]] to update an [[error term]] that determines if another quantity is incremented, avoiding the need for expensive [[division (mathematics)|division]] or [[multiplication]] operations; e.g. [[bresenham's line algorithm]], or [[voxel#Incremental error rasterization|rasterizing]] [[#heightmap|heightmap]] landscapes.<ref>{{cite web|title=Incremental error landscape rendering - "voxel space"|date = 30 April 2020|url=http://simulationcorner.net/index.php?page=comanche}}</ref>
}}

{{term|Index buffer}}
{{defn|A rendering resource used to define rendering primitive connectivity information between [[Vertex (computer graphics)|vertices]].}}

{{term|Indirect illumination}}
{{defn|Another term for [[global illumination]].}}

{{term|[[Geometry instancing|Instancing]]}}
{{defn|Rendering multiple objects (instances) using the same geometry data.}}

{{term|Intersection test}}
{{defn|Determining if two pieces of [[geometry]] [[Intersection (mathematics)|intersect]], commonly required in [[simulation]], [[rendering pipeline]]s, and [[3D modelling]] applications.
}}

{{end glossary}}

== K ==
{{glossary}}

{{term|K-DOP}}
{{defn|A type of [[bounding volume]] used for fast intersection tests; a [[Bounding volume#discrete oriented polytope|discrete oriented polytope (DOP)]]. These generalise [[bounding box]]es with [[#extents|extents]] additional discrete [[Plane (geometry)|plane]]s (e.g. diagonals formed by each pair of coordinate axes, etc.).}}

{{end glossary}}

== L ==
{{glossary}}
{{term|[[Level of detail (computer graphics)|Level of detail]] (LOD)}}
{{defn|If an object contributes less to the rendered result, e.g. by being far away from the camera, LOD chooses to use a simpler version of the object (e.g. with fewer polygons or textures).<ref name="akenine" />{{rp|852}}}}

{{term|Light probe}}
{{defn|Object used to capture light parameters at a specific point in space in order to help compute scene lighting.<ref>{{cite web |title=Light Probes: Introduction |url=https://docs.blender.org/manual/en/latest/render/eevee/light_probes/introduction.html |website=Blender Manual |access-date=25 April 2020}}</ref>}}

{{term|Low level rendering API}}
{{defn|A library providing a minimal [[abstraction layer]] over a [[graphics processing unit]]'s raw command lists, such as [[Vulkan (API)|Vulkan]], [[LibGCM]], or [[Metal (API)]]. The user typically has more control over (and responsibility for) [[rendering resource|resource]] management, [[command buffers]], synchronization issues.}}

{{term|[[Computer graphics lighting|Lighting]]}}
{{defn|Computations simulating the behavior of light.}}

{{term|Light vector}}
{{defn|In shading calculations, a [[#3d unit vector|3d unit vector]] representing the direction of [[incident light]] onto a model's surface.}}

{{term|Light field|content=[[Light field]]}}
{{defn|A [[data structure]] approximating the [[4D flux]]  of [[light rays]] through a space (or in the general case, 5D); it may be captured using multiple cameras (e.g. [[light stage]]), or rendered from a [[3D modeling|3D model]] by [[ray tracing (graphics)|ray tracing]].}}

{{term|Line primitive}}
{{defn|A rendering primitive or modelling primitive representing a [[line segment]], used for [[wire-frame model|wireframes]].}}

{{term|Lumels}}
{{defn|A term for [[texel]]s in the [[texture map]] representing a [[lightmap]].}}

{{end glossary}}

== M ==
{{glossary}}

{{term|[[Taxicab geometry|Manhattan distance]]}}
{{defn|Measure of distance between two points, different from [[Euclidean distance]], that sums the distances along principal axes.}}

{{term|Marching cubes|content=[[Marching cubes]]}}
{{defn|A method for triangulating [[implicit surface]]s.}}

{{term|MegaTexturing}}
{{defn|Texturing technique that works with extremely large textures which are not loaded into memory all at once, but rather streamed from the [[hard disk]] depending on the camera view.<ref name="ahearn">{{cite book |last1=Ahearn |first1=Luke |title=3D Game Environments: Create Professional 3D Game Worlds |date=2017 |publisher=CRC Press, Taylor & Francis |isbn=978-1-138-92002-6 |edition=second}}</ref>{{rp|176}}}}

{{term|Microtexture}}
{{defn|An alternative term sometimes used for Detail textures.}}

{{term|Mipmapping|content=[[Mipmap]]}}
{{defn|Method of preventing [[aliasing]] by storing differently scaled versions of the same image and using the correct one during rendering.}}

{{term|Modelling primitive}}
{{defn|Basic elements from which [[3D modeling|3D models]] and 3D scenes are composed. Also known as a [[Geometric primitive]].}}

{{term|Model space}}
{{defn|Coordinate system in which a 3D model is created and stored.}}

{{term|Model transformation matrix}}
{{defn|A [[transformation matrix]] producing [[world coordinates]] from a [[3D modeling|3D model]]'s [[local coordinates]].}}

{{term|Multiply blend|content=[[Blend modes#Multiply|Multiply blend]]}}
{{defn|A [[blending operation]] used for [[lightmap]]s, <math>dst=dst*src.</math>}}

{{end glossary}}

== N ==
{{glossary}}

{{term|Near clipping}}
{{defn|The clipping of 3D [[rendering primitives]] against the near clip plane. Necessary to correctly display rendering primitives that partially pass behind the [[#camera|camera]].}}

{{term|Nearest neighbor filtering|content=[[Nearest-neighbor interpolation]]}}
{{defn|Simplest form of interpolation that for given position outputs the color of the nearest sample.}}

{{term|[[Noise (signal processing)|Noise]]}}
{{defn|In real world data a noise is an unwanted distortion of the captured signal, e.g. in photography. In rendering, artificial noise, such as [[white noise]] or [[Perlin noise]], is often generated and added on purpose to add realism.}}

{{term|Normal mapping|content=[[Normal mapping]]}}
{{defn|Method of adding detail to the surface of 3D models, without increasing geometry complexity, by using a texture with precomputed normals that are used during shading.}}

{{end glossary}}

== O ==
{{glossary}}
{{term|[[Wavefront .obj file|OBJ]] format}}
{{defn|A common 3D file format.}}

{{term|[[Image and object order rendering|Object order rendering]]}}
{{defn|Rendering methods that iterate over objects in the scene and draws then one by one (e.g. [[rasterization]]).}}

{{term|[[Occlusion culling]]}}
{{defn|Culling (discarding) of objects before rendering that are completely obscured by other objects.}}

{{term|Occlusion query}}
{{defn|A command passed to a [[graphics processing unit]] requesting the testing of [[bounding volume]] geometry against the [[depth buffer]] to determine if any contents in the [[potentially visible set]]; used for [[hardware accelerated]] [[occlusion culling]].}}

{{term|Offline rendering}}
{{defn|Non-real-time rendering.}}

{{term||OOBB}}
{{defn|An [[object oriented bounding box]] (sometimes called object aligned); a [[bounding box]] stored in some object's [[local coordinate system]]}}

{{term|[[OpenGL]]}}
{{defn|Commonly used 2D and 3D graphics rendering [[API]].}}

{{term|Outcode}}
{{defn|A small [[integer]] holding a bit for the result of every plane test (or clip window edge test) failed in [[clipping (computer graphics)|clipping]]. Primitives may be trivially rejected if the [[bitwise AND]] of all its [[vertex (computer graphics)|vertices]] outcodes is non zero}}

{{end glossary}}

== P ==
{{glossary}}

{{term|Packed pixel format}}
{{defn|An [[#image format|image format]] where the [[channel (digital image)|image channels]] are interleaved contiguously in [[memory (computing)|memory]], possibly containing multiple channels within single [[machine word]]s, equivalent to an [[array of structure]]s for bitmap data. Contrasts with [[#planar image format|planar image format]]s.}}

{{term|Parallax mapping|content=[[Parallax mapping]]}}
{{defn|Shader effect that adds detail with a sense of depth to a 3D surface, in a more realistic way than normal mapping.}}

{{term|Parameter gradient}}
{{defn|The [[derivative]] of a vertex attribute with respect to screen space [[coordinates]] during [[rasterization]], used for [[interpolation]] across a rendering primitive surface.}}

{{term|[[Particle system|Particle effect]]}}
{{defn|Effects consisting of a number of particles that behave by certain rules, typically used to simulate fire, smoke etc.<ref name="akenine" />{{rp|567}}}}

{{term|Path tracing|content=[[Path tracing]]}}
{{defn|Photorealistic iterative rendering method based on tracing light paths.}}

{{term|[[Texture mapping#Perspective correctness|Perspective correct texturing]]}}
{{defn|Non-linear texture coordinate interpolation that takes into account perspective, eliminating distortion seen in affine texture mapping.}}

{{term|[[Phong reflection model|Phong lighting]]}}
{{defn|A commonly used model of local illumination that computes the result as a sum of ambient, diffuse and specular elements of light.}}

{{term|[[Phong shading]]}}
{{defn|Shading technique that uses interpolated normals.}}

{{term|[[Photogrammetry]]}}
{{defn|Science and technology of making measurement from photographs, e.g. automatically creating 3D models of environment.}}

{{term|[[Photometry (optics)|Photometry]]}}
{{defn|Science of measuring light in terms of human perception.}}

{{term|Photon mapping|content=[[Photon mapping]]}}
{{defn|Photorealistic rendering algorithm based on tracing rays from the camera as well as light sources, able to simulate effects such as [[caustic (optics)|caustic]]s.}}

{{term|[[Physically based rendering]] (PBR)}}
{{defn|[[Rendering algorithm]]s based on [[physics simulation]] of [[light]], including [[conservation of energy]], [[empirical model]]s of surfaces.<ref>{{Cite web|url=https://www.pbrt.org/|title=Physically Based Rendering: From Theory to Implementation|website=www.pbrt.org}}</ref>
}}

{{term|Pixel|content=[[Pixel]]}}
{{defn|Smallest element of a raster image.}}

{{term|Planar image format}}
{{defn|An [[#image format|image format]] where the image channels (or even bits) for a single [[pixel]] is separated into several [[parallel array]]s, equivalent to a [[structure of arrays]] for bitmap data.}}

{{term|Point cloud|content=[[Point cloud]]}}
{{defn|A surface defined by a collection of [[Vertex (computer graphics)|vertices]] without [[#connectivity information|connectivity information]].<ref>{{Cite web|url=http://www.enseignement.polytechnique.fr/informatique/INF555/Slides/lecture7.pdf|title=Geometric Modeling: Digital Representation and Analysis of Shapes|archive-url=https://web.archive.org/web/20160819151452/http://www.enseignement.polytechnique.fr/informatique/INF555/Slides/lecture7.pdf|archive-date=19 August 2016|access-date=7 June 2016|url-status=live}}</ref>
}}

{{term|Point sprite}}
{{defn|A rendering primitive in <!--note [[3d graphics pipelines]] links (incorrectly?) to here, unlike new: -->[[3D graphics pipeline]]s, allowing one vertex plus radius to define a [[billboard]]; corner vertices are automatically generated. Typically used for [[particle systems]]}}

{{term|Polygon mesh|content=[[Polygon mesh]]}}
{{defn|A [[3D modeling|3D model]] consisting of [[vertex (computer graphics)|vertices]] connected by [[polygon primitive]]s.}}

{{term|Polygon primitive}}
{{defn|A rendering or modelling primitive defining a flat surface connecting 3 or more [[Vertex (computer graphics)|vertices]].}}

{{term|Portal|content=[[Portal rendering#Portal|Portal]]}}
{{defn|A means of [[occlusion culling]], defining a visible window between adjacent [[bounding volume]]s, used in [[portal rendering]].}}

{{term|Post processing}}
{{defn|Effects applied to a [[bitmap image]] in screen space after [[3D rendering pipeline]], for example [[tone mapping]], some approximations to [[motion blur#Computer graphics|motion blur]], and [[bloom (shader effect)|bloom]]s.<ref>{{Cite web|url=https://docs.unrealengine.com/5.2/en-US/post-process-effects-in-unreal-engine/|title=Post Process Effects in Unreal Engine|website=docs.unrealengine.com|publisher = Epic Games}}</ref>
}}

{{term|Predicated rendering}}
{{defn|A feature facilitating [[occlusion culling]] within a [[graphics pipeline]], performed by a command list asynchronously form the [[CPU]], where a group of rendering commands are flagged to be conditional on the result of an earlier occlusion query.}}

{{term|Premultiplied alpha}}
{{defn|A variation of a [[bitmap image]] or [[alpha blending]] calculation in which the RGB color values are assumed to be already multiplied by an alpha channel, to reduce computations during [[alpha blending]]; uses the [[blend operation]]: {{code|1= dst *= (1 - alpha) + src}}; capable of mixing alpha blending with [[additive blending]] effects}}

{{term|Primitive}}
{{defn|A basic unit of [[geometry]] for rendering or modelling.}}

{{term|Procedural generation|content=[[Procedural generation]]}}
{{defn|Generating data, such as [[Procedural texture|texture]]s, 3D geometry or whole scenes by algorithms (as opposed to manually).}}

{{term|[[Procedural texture]]}}
{{defn|A texture (very often a volume texture) generated procedurally by a mathematical function and with the use of noise functions.<ref name="akenine">{{cite book |last1=Akenine-Möller |first1=Tomas |last2=Haines |first2=Eric |last3=Hoffman |first3=Naty |title=Real-Time Rendering |date=2018 |publisher=CRC Press, Taylor & Francis |isbn=978-1-1386-2700-0 |edition=Fourth}}</ref>{{rp|198}}}}

{{end glossary}}

== Q ==
{{glossary}}
{{term|[[Quaternion]]}}
{{defn|A means of representing [[rotation (geometry)|rotation]]s in a 4D vector, useful for [[skeletal animation]], with advantages for [[interpolation]] compared to [[euler angles]] (i.e. not suffering from [[gimbal lock]]).<ref>{{cite web|title=quaternions for rotations|url=http://run.usc.edu/cs520-s15/quaternions/quaternions-cs520.pdf|access-date=10 June 2016|archive-date=7 October 2016|archive-url=https://web.archive.org/web/20161007031227/http://run.usc.edu/cs520-s15/quaternions/quaternions-cs520.pdf|url-status=dead}}</ref>
}}

{{end glossary}}

== R ==
{{glossary}}
{{term|[[Radiometry]]}}
{{defn|Measurement of electromagnetic radiation such as light, defining measures such as [[flux]] or [[radiance]].<ref name="gomes">{{cite book |last1=Gomes |first1=Jonas |last2=Velho |first2=Luiz |last3=Mario |first3=Costa Sousa |title=Computer Graphics, Theory and Practice |date=2012 |publisher=CRC Press |isbn=978-1-4398-6557-6}}</ref>{{rp|469}}}}

{{term|Raster graphics|content=[[Raster graphics]]}}
{{defn|Graphics represented as a rectangular grid of pixels.}}

{{term|Rasterization|content=[[Rasterisation|Rasterization]]}}
{{defn|Converting vector graphics to raster graphics. This terms also denotes a common method of rendering 3D models in real time.}}

{{term|Ray casting|content=[[Ray casting]]}}
{{defn|Rendering by casting non-recursive rays from the camera into the scene. 2D ray casting is a [[2.5D]] rendering method.}}

{{term|Ray marching|content=[[Ray marching]]}}
{{defn|Sampling 3D space at multiple points along a ray, typically used when analytical methods cannot be used.<ref name="driemeyer">{{cite book |last1=Driemeyer |first1=Thomas |title=Rendering with mental ray |date=2001}}</ref>{{rp|157}}}}

{{term|Ray tracing|content=[[Ray tracing (graphics)|Ray tracing]]}}
{{defn|Recursively tracing paths of [[light rays]] through a 3D scene, may be used for [[3D rendering]] (more commonly for offline rendering), or other tests.}}

{{term|Recursive subdivision|content=Recursive subdivision}}
{{defn|The process of [[subdivision (computer graphics)|subdividing]] an object (either geometric object, or a data structure) [[recursion (computer science)|recursively]] until some criterion is met.}}

{{term|Render mapping}}
{{defn|The [[Baking (computer graphics)|baking]] of a rendering of a [[3D modeling|3D model]] surface into a [[texture map]] to capture surface properties. Also known as 'render surface map'.<ref>{{Cite web|url=http://help.autodesk.com/cloudhelp/2015/ENU/3DSMax/files/GUID-08738349-9267-4D9C-986F-C6198E9AA900.htm#!|title=Render Surface Map|website=help.autodesk.com}}</ref><ref>{{Cite web|url=https://download.autodesk.com/global/docs/softimage2014/en_us/userguide/index.html?url=files/rendermap_RendermappingMultipleObjects.htm,topicNumber=d30e601778|title=Softimage User Guide|website=download.autodesk.com}}</ref>
}}

{{term|Render pass}}
{{defn|A stage in a [[rendering pipeline]] generating some (possibly incomplete) representation of the scene.}}

{{term|Render states}}
{{defn|Information controlling a [[graphics pipeline]], composed of modes and parameters, including resource identifiers, and [[shader]] bindings.}}

{{term|Render target}}
{{defn|A graphics resource into which [[rendering primitives]] are [[rasterized]] by a [[graphics pipeline]]. Render targets may be [[frame buffer]]s or [[texture maps]].}}

{{term|Render to texture}}
{{defn|The process of [[rasterizing]] into a [[texture map]] (or texture buffer) for further use as a resource in subsequent render passes. Used for [[environment mapping]], impostor rendering, [[shadow mapping]] and [[#post processing|post-processing]] filters. Requires the ability to use a [[texture map]] as a [[render target]].}}

{{term|Rendering API|content=[[List of rendering APIs|Rendering API]]}}
{{defn|A [[software library]] for submitting rendering commands, and managing render states and rendering resources. Examples include [[OpenGL]], [[Vulkan (API)|Vulkan]], [[Direct3D]], and [[Metal (API)|Metal]]. Provides an abstraction layer for a [[graphics processing unit]].}}

{{term|Rendering command}}
{{defn|An instruction for [[rasterizing]] geometry in a [[3D graphics pipeline]], typically held in a command buffer, or submitted programmatically through a [[rendering API]].}}

{{term|Rendering equation|content=[[Rendering equation]]}}
{{defn|Mathematical equation used as a model of light behavior in photorealistic rendering.}}

{{term|Rendering primitive}}
{{defn|Geometry that can be drawn by a [[rasterizer]] or [[graphics processing unit]], connecting [[vertex (computer graphics)|vertices]], e.g. points, [[line primitive|line]]s, triangles, quadrilaterals}}

{{term|Rendering resources}}
{{defn|Data managed by a graphics API, typically held in [[device memory]], including vertex buffers, index buffers, [[texture maps]] and [[framebuffer]]s}}

{{term|Repeating texture}}
{{defn|A [[texture map]] applied with wrap-round UV coordinates extending between the 0–1 range (representing one unit of the image), exhibiting [[frequency|periodicity]]. Contrasts with clamped, mirrored modes or unique mappings.}}

{{term|Resource}}
{{defn|Data (often held in a buffer managed by a rendering API) read by a [[graphics pipeline]], e.g. [[texture map]]s, vertex buffers, [[shader]]s, index buffers, or other pieces of [[3D modeling|3D model]] data.}}

{{term|RGB888}}
{{defn|An RGB color value encoded as [[8-bit color|8 bits]] per [[channel (digital image)|channel]].}}

{{term|RGBA|content=[[RGBA]]}}
{{defn|An RGB color value together with an alpha channel, typically held in [[bitmap image]]s or intermediates in [[#shading calculation|shading calculation]]s.}}
{{term|RGBA888}} {{defn|an RGBA color value encoded as [[8-bit color|8 bits]] per [[channel (digital image)|channel]]}}

{{term|RGB color value}}
{{defn|A [[3D vector]] describing a color using the [[RGB color model]]; may use [[fixed-point arithmetic|fixed-point]] or [[floating-point arithmetic|floating-point]] representations.}}

{{term|RGB image}}
{{defn|A [[bitmap image]] holding RGB color values in 3 [[channel (digital image)|image channel]]s}}

{{term|Rounding radius}}
{{defn|A value used in smoothing the corners of a [[geometric figure]] such as a [[2D polygon]] or [[3D polygon mesh]].<ref>{{Cite web|url=https://reference.wolfram.com/language/ref/RoundingRadius.html.en|title=RoundingRadius—Wolfram Language Documentation|website=reference.wolfram.com}}</ref>}}

{{end glossary}}

== S ==
{{glossary}}
{{term|Scene graph|content=[[Scene graph]]}}
{{defn|[[Data structure]] commonly used to represent a 3D scene to be rendered as a [[directed acyclic graph]].}}

{{term|Screen space}}
{{defn|The [[coordinate space]] of the resulting [[#2d image|2d image]] during [[3D rendering]]. The result of [[3D projection]] on [[geometry]] in [[camera space]].}}

{{term|[[Screen space ambient occlusion]] (SSAO)}}
{{defn|Technique of approximating ambient occlusion in screen space.}}

{{term|Screen space directional occlusion}}
{{defn|An enhancement of [[screen space ambient occlusion]] (SSAO) taking direction into account to sample the [[#ambient light|ambient light]], to better approximate [[global illumination]].<ref>{{Cite web|url=https://people.mpi-inf.mpg.de/~ritschel/Papers/SSDO.pdf|title=Max-Planck-Institut für Informatik: Data Protection|website=people.mpi-inf.mpg.de}}</ref>}}

{{term|Shader|content=[[Shader]]}}
{{defn|A subroutine written in a [[shading language]] describing: [[vertex transformation]]s, skinning, and possibly [[vertex lighting]] (in [[vertex shader]]s); [[#shading calculation|shading calculation]]s (in [[pixel shader]]s); control over [[tessellation (computer graphics)|tessellation]] ([[tessellation shader]]s); or [[compute shader|general purpose computation]].}}

{{term|Shading calculation}}
{{defn|[[Surface lighting]] and [[texturing blending]] operations, e.g. including [[specularity]], [[bump mapping]] etc.}}

{{term|Shadow buffer}}
{{defn|A synonym for shadow map.}}

{{term|Shadow map}}
{{defn|A texture buffer holding depth values rendered in a separate render pass from the perspective of a [[lightsource]], used in [[Shadow mapping]]; it is typically rendered onto other geometry in the main rendering pass.<ref>{{Cite web|url=https://www.google.co.uk/search?client=safari&rls=en&q=shadow+mapping+sigraph&ie=UTF-8&oe=UTF-8&gfe_rd=cr&ei=Ci9aV8y-Au3a8AfS3qeACg|title=shadow mapping sigraph - Google Search|website=www.google.co.uk}}</ref>
}}

{{term|Shadow volume|content=[[Shadow volume]]}}
{{defn|One of the techniques of adding shadows to 3D scenes.}}

{{term|Signed triangle area}}
{{defn|Found using half the Z component of [[cross product]] of a pair of screen-space triangle edge vectors, useful for [[backface culling]] and computing parameter gradients in [[triangle rasterization]].}}

{{term|[[Skybox (video games)|Skybox]]}}
{{defn|Method of creating background for a 3D scene by enclosing it in a textured cuboid (or another environment map).<ref name="akenine" />{{rp|547}}}}

{{term|Sliverous triangle}}
{{term|Sliver triangle}}
{{defn|A triangle with one or two extremely [[acute angle]]s, hence a long/thin shape, which has undesirable properties during some [[interpolation]] or [[rasterization]] processes.<ref>{{Cite web|url=http://www.cs.iit.edu/~xli/paper/Conf/sliver-STOC00.pdf|title=cleanup of sliver triangles|accessdate=6 August 2023}}</ref>
}}

{{term|[[Software renderer]]}}
{{defn|Rendering software that doesn't use specialized hardware (a [[GPU]]) for its computations, i.e. only uses [[CPU]] for rendering.}}

{{term|Sparse texture}}
{{defn|A texture that can partially reside in the video memory to reduce video memory usage and loading time.}}

{{term|Spatial hashing}}
{{defn|A form of [[hash function|hashing]] to accelerate [[spatial testing]] e.g. for [[AI]], [[collision detection]], typically using a [[#grid cell index|grid cell index]] as a [[Key (hash table)|key]].}}

{{term|Specular exponent}}
{{defn|Controls the glossiness in the [[Phong shading]] model.}}

{{term|Specular highlights}}
{{defn|In shading, specular highlight is a bright highlight caused by specular [[reflection (computer graphics)|reflections]], more prominent on metallic surfaces. These highlights depend on the viewer's position as well as the position of the light source and surface normal.}}

{{term|Spline}}
{{defn|A [[curve]] defined by [[polynomial interpolation]] through [[control point (mathematics)|control points]].}}

{{term|[[Sprite (computer graphics)|Sprite]]}}
{{defn|2D image moving on the screen, with potential partial transparency and/or animation.<ref name="akenine" />{{rp|550}}}}

{{term|State changes}}
{{defn|The passing of changes in render states in a [[graphics pipeline]], incurring a performance overhead. This overhead is typically minimised by scene [[sorting (computer science)|sorting]].}}

{{term|Stencil buffer|content=[[Stencil buffer]]}}
{{defn|A buffer storing an integer value for each according screen pixel, used e.g. to mask out specific operations and achieve specific effects.}}

{{term|Stereo rendering}}
{{defn|Rendering the view twice separately for each eye in order to present [[stereopsis|depth]].}}

{{term|Surface normal vector}}
{{defn|In shading calculations, the [[Normal (geometry)|normal]] to a [[3D modeling|3D model]] surface, typically compared with the light and view vectors to compute the resulting visible colour. Also used for [[displacement mapping]].}}

{{term|Swizzled texture}}
{{defn|A [[texture map]] stored out of the natural pixel order; see [[swizzling (computer graphics)]]. For example, it may be stored in [[morton order]], giving improved [[cache coherency]] for 2D [[memory access pattern]]s.<ref>{{cite web|title=Optimizing Memory Access on GPUs using Morton Order Indexing|url=http://john.cs.olemiss.edu/~rhodes/papers/Nocentino10.pdf|access-date=10 June 2016|archive-date=15 August 2020|archive-url=https://web.archive.org/web/20200815023648/https://john.cs.olemiss.edu/~rhodes/papers/Nocentino10.pdf|url-status=dead}}</ref>
}}

{{end glossary}}

== T ==
{{glossary}}

{{term|Terrain rendering|content=[[Terrain rendering]]}}
{{defn|Rendering of [[landscape]]s, typically using [[heightmap]]s or [[voxel]]s.}}

{{term|[[Tessellation (computer graphics)|Tessellation]]}}
{{defn|Converting a general 3D surface into polygonal representation, important because of HW being optimized for rendering polygons.<ref name="akenine" />{{rp|683}}}}

{{term|Texel}}
{{defn|Texture element, a pixel of a texture.}}

{{term|Texture cache}}
{{defn|A specialised read-only [[cache (computing)|cache]] in a [[graphics processing unit]] for buffering [[texture map]] reads, accelerating texture sampling operations.}}

{{term|Texture sampling|content=Texture sampling}}
{{defn|The process of [[texture lookup]] with [[texture filtering]]. Performed by a texture sampling unit in a [[graphics processing unit]]}}

{{term|Texture sampling unit}}
{{defn|A [[fixed-function unit]] performing texture sampling; also known as a [[texture mapping unit]].}}

{{term|Texture buffer}}
{{defn|A region of [[Memory (computing)|memory]] (or resource) used as both a render target and a [[texture map]].}}

{{term|Texture map|content=[[Texture map]]}}
{{defn|A [[bitmap image]]/rendering resource used in [[texture mapping]], applied to [[3D modeling|3D models]] and indexed by [[UV mapping]] for [[3D rendering]].}}

{{term|Texture space}}
{{defn|The [[coordinate space]] of a [[texture map]], usually corresponding to UV coordinates in a [[3D modeling|3D model]]. Used for some [[rendering algorithm]]s such as [[texture space diffusion]]}}

{{term|Transform feedback}}
{{defn|A feature of a [[rendering pipeline]] where transformed vertices may be written back to a buffer for later use (e.g. for re-use in additional [[render pass]]es or subsequent rendering commands), e.g. caching the result of [[skeletal animation]] for use in [[shadow rendering]].<ref>{{Cite web|url=https://open.gl/feedback|title=OpenGL - Transform Feedback|website=open.gl}}</ref>
}}

{{term|Triangulation|content=[[Surface triangulation|Triangulation]]}}
{{defn|The process of turning arbitrary geometric models into [[triangle primitive]]s, suitable for [[algorithm]]s requiring [[triangle mesh]]es}}

{{term|Triangle primitive}}
{{defn|The most common rendering primitive defining [[triangle mesh]]es, rendered by [[graphics processing unit]]s}}

{{term|Triangle setup}}
{{defn|The process of ordering triangle primitive vertices, calculating [[#signed triangle area|signed triangle area]] and parameter gradients between vertex attributes as a prerequisite for [[rasterization]].<ref name="triangle setup">{{Cite web|url=http://citeseerx.ist.psu.edu/viewdoc/download?rep=rep1&type=pdf&doi=10.1.1.52.3080|title=triangle setup|accessdate=6 August 2023}}</ref>
}}

{{term|Triangle setup unit}}
{{defn|A [[fixed-function unit]] in a [[graphics processing unit|GPU]] that performs triangle setup (and may perform [[backface culling]]), prior to actual [[rasterization]].<ref name="triangle setup"/>
}}

{{term|Trilinear filtering|content=[[Trilinear filtering]]}}
{{defn|Extension of bilinear filtering that additionally linearly interpolates between different [[mipmap]] levels of the texture, eliminating sharp transitions.}}

{{term|Triple buffering}}
{{defn|Improvement of double buffering for extra performance by adding another back buffer.}}

{{term|Tristrip|content=[[Triangle strip|Tristrip]]}}
{{defn|A common rendering primitive defining a sequence of adjacent [[triangle primitive]]s, where each triangle re-uses 2 [[vertex (computer graphics)|vertices]] from the previous one.}}

{{term|Trivial accept}}
{{defn|The process of accepting an entire [[rendering primitive]], [[3D modeling|3D model]], or [[bounding volume]] contents without further tests for [[clipping (computer graphics)|clipping]] or [[occlusion culling]]. The opposite of trivial rejection.}}

{{term|Trivial rejection}}
{{defn|Rejecting a rendering primitive or [[3D modeling|3D model]] based on a cheap calculation performed early in a [[graphics pipeline]], (e.g. using [[#outcode|outcode]]s in [[clipping (computer graphics)|clipping]]). The opposite of trivial accept.}}

{{end glossary}}

== U ==
{{glossary}}

{{term|Unified memory}}
{{defn|A [[memory architecture]] where the [[CPU]] and [[GPU]] share the same [[address space]], and often the same [[physical memory]]. It is common in Intel<ref>{{Cite web|url=https://www.intel.com.au/content/www/au/en/support/articles/000020962/graphics.html|title = Frequently Asked Questions for Intel® Graphics Memory on}}</ref><ref>{{cite web|url=https://software.intel.com/content/dam/develop/external/us/en/documents/the-compute-architecture-of-intel-processor-graphics-gen9-v1d0.pdf|title=The Compute Architecture of Intel® Processor Graphics Gen9|website=Intel®|access-date=6 August 2023}}</ref> and AMD<ref>{{cite web | title=Configuring UMA Frame Buffer Size on Desktop Systems with Integrated Graphics | website=AMD | date=31 March 2021 | url=https://www.amd.com/en/support/kb/faq/pa-280 | access-date=6 August 2023}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/7677/amd-kaveri-review-a8-7600-a10-7850k/6|title = AMD Kaveri Review: A8-7600 and A10-7850K Tested}}</ref> processors with integrated graphics, [[System on a chip|SoC]]s and [[video game console]]s. Supported on some [[discrete GPU]]s with the use of an [[memory management unit|MMU]].}}

{{term|UV coordinates}}
{{defn|[[Coordinates]] in [[texture space]], assigned as vertex attributes and/or calculated in [[vertex shader]]s, used for [[texture lookup]], defining the mapping from texture space to a [[3D modeling|3D model]] surface or any rendering primitive.}}

{{term|UV unwrapping|content=[[UV mapping#UV unwrapping|UV unwrapping]]}}
{{defn|The process of flattening a [[3D modeling|3D model]]'s surface into a flat [[2D plane]] in a contiguous, spatially coherent manner for [[texture mapping]].}}

{{end glossary}}

== V ==
{{glossary}}

{{term|Vector graphics|content=[[Vector graphics]]}}
{{defn|Graphics represented as a set of geometrical primitives.}}

{{term|Vector maths library}}
{{defn|A library defining mathematical operations on [[vector space]]s used in [[3D graphics]], concentrating on [[3D vector|3D]] and 4D vectors, and 4x4 matrices, often with optimised [[SIMD]] implementations.<ref>{{Cite news|url=https://forum.beyond3d.com/threads/sony-open-sources-vector-math-and-simd-math-libraries-cell-ppu-spu-other-platforms.38677/|title=Sony open sources Vector Math and SIMD math libraries (Cell PPU/SPU/other platforms)|work=Beyond3D Forum|access-date=2018-11-03|language=en-US|archive-date=24 June 2016|archive-url=https://web.archive.org/web/20160624183718/https://forum.beyond3d.com/threads/sony-open-sources-vector-math-and-simd-math-libraries-cell-ppu-spu-other-platforms.38677/|url-status=dead}}</ref>}}

{{term|Vertex buffer|content=[[Vertex Buffer Object#vertex buffer|Vertex buffer]]}}
{{defn|A rendering resource managed by a rendering API holding [[vertex (computer graphics)|vertex]] data. May be connected by primitive indices to assemble rendering primitives such as [[triangle strip]]s. Also known as a [[Vertex buffer object]] in [[OpenGL]].}}

{{term|Vertex cache}}
{{defn|A specialised read-only [[Cache (computing)|cache]] in a [[graphics processing unit]] for buffering indexed vertex buffer reads.}}

{{term|Vertex shader|content=[[Vertex shader]]}}
{{defn|Shader processing vertices of a 3D model.}}

{{term|View transformation}}
{{defn|A [[Matrix (mathematics)|matrix]] transforming world space coordinates into [[camera space]].}}

{{term|View vector}}
{{defn|In shading calculations, a 3D unit vector between the [[camera]] and the point of interest on a surface.}}

{{term|[[View frustum]]}}
{{defn|A truncated pyramid enclosing the subset of 3D space that projects onto a 'viewport' (a rectangular region in screen space, usually the entire screen).}}

{{term|[[Virtual reality]]}}
{{defn|Computer-rendered content that (unlike [[augmented reality]]) completely replaces the user's view of the real world.<ref name="akenine" />{{rp|915}}}}

{{term|Volume texture}}
{{defn|A type of [[texture map]] with 3 dimensions.}}

{{term|Voxel|content=[[Voxel]]}}
{{defn|An extension of [[pixel]]s into 3 dimensions.}}

{{term|VSync}}
{{defn|Vertical synchronization, synchronizes the rendering rate with the monitor refresh rate in order to prevent displaying only partially updated frame buffer, which is disturbing especially with horizontal camera movement.}}

{{term|[[Vulkan (API)|Vulkan]]}}
{{defn|High-performance, low-level graphics API by [[Khronos Group]].}}

{{end glossary}}

== W ==
{{glossary}}

{{term|W buffering}}
{{defn|A [[depth buffer]] storing inverse depth values, which has some advantages for [[interpolation]] and precision scaling.}}

{{term|Weight map}}
{{defn|A set of Vertex attributes controlling deformation of a [[3D modeling|3D model]] during [[skeletal animation]]. Per-[[vertex (computer graphics)|vertex]] [[weighting|weights]] are assigned to control the influence of multiple bones (achieved by interpolating the transformations from each).<ref>{{cite web|title=weight maps|url=http://softimage.wiki.softimage.com/xsidocs/weightmaps_WeightMaps.htm|access-date=2016-06-10|archive-url=https://web.archive.org/web/20160531213127/http://softimage.wiki.softimage.com/xsidocs/weightmaps_WeightMaps.htm|archive-date=2016-05-31|url-status=dead}}</ref>
}}

{{term|Window|content=[[Window (computing)|Window]]}}
{{defn|A rectangular region of a screen or [[bitmap image]].}}

{{term|Wireframe}}
{{defn|May refer to [[wireframe model]]s or [[wireframe rendering]].}}

{{term|Wireframe rendering}}
{{defn|A rendering of a [[3D modeling|3D model]] displaying only [[edge (computer graphics)|edge]] [[#connectivity information|connectivity]]; used in [[3D modelling application]]s for greater interactive speed, and clarity for [[mesh editing]].}}

{{term|World space}}
{{defn|The global [[coordinate system]] in a 3D scene, reached by applying a [[#model transformation matrix|model transformation matrix]] from the objects' [[local coordinates]].}}

{{end glossary}}

== Z ==
{{glossary}}

{{term|Z buffer|content=[[Z buffer]]}}
{{defn|A [[2D array]] holding depth values in screen space; a component of a [[framebuffer]]; used for [[hidden surface determination]].}}

{{term|Z order|content=[[Z order]]}}
{{defn|A [[Morton order]] [[space filling curve]], useful for increasing [[cache coherency]] of spatial traversals.}}

{{term|Z test culling}}
{{defn|A form of [[occlusion culling]] by testing [[bounding volume]]s against a [[Z buffer]]; may be performed by a [[graphics processing unit]] using occlusion queries.}}

{{glossary end}}

== References ==
{{Reflist}}

{{Glossaries of computers}}

[[Category:Computer graphics]]
[[Category:Video game graphics]]
[[Category:Glossaries of computers|Graphics]]
[[Category:Wikipedia glossaries using description lists]]