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A common datatype in graphics code, holding homogeneous coordinates or RGBA data, or simply a 3D vector with unused W to benefit from alignment, naturally handled by machines with 4-element SIMD registers.
Unwanted effect arising when sampling high-frequency signals, in computer graphics appearing e.g. when downscaling images. Antialiasing methods can prevent it.
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.[3]: 446
Computer-rendered content inserted into the user's view of the real world.[3]: 917
AZDO
Approaching zero driver overhead, a set of techniques aimed at reducing the 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.[5]
Modification of ray tracing which instead of lines uses pyramid-shaped beams to address some of the shortcomings of traditional ray tracing, such as aliasing.[7]
A render state controlling alpha blending, describing a formula for combining source and destination pixels.
Bone
Coordinate systems used to control surface deformation (via Weight maps) during skeletal animation. Typically stored in a hierarchy, controlled by key frames, and other procedural constraints.
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).[3]: 819
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.
Color channels
The set of channels in a bitmap image representing the visible color components, i.e. distinct from the alpha channel or other information.
Before rendering begins, culling removes objects that don't significantly contribute to the rendered result (e.g. being obscured or outside camera view).[3]: 830
D
Decal
A "sticker" picture applied onto a surface (e.g. a crack on the wall).[3]: 888
Detail texture
Texture maps repeated at high frequency combined with a main texture on a surface to prevent a blurred appearance close to the camera.
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.[3]: 884
Deformation lattice
A means of controlling free-form deformation via a regular 3D grid of control points moved to arbitrary positions, with polynomial interpolation of the space between them.
Degenerate triangles
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.[11]
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.
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.
Drawcall
A single rendering command submitted to a rendering API, referring to a single set of render states.
Also reflection mapping, a technique of approximating reflections of environment on complex surfaces of 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.)
Extents
The minimum and maximum values of an object or primitive along a coordinate axis or set of axes.
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.
According to Fresnel equations, surfaces show more specular reflections when viewed at near-grazing incidence. This effect is often simulated in computer graphics.
An approximate antialiasing method performed in a 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).
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).
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.
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 indirectly from resources.
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).[3]: 852
Light probe
Object used to capture light parameters at a specific point in space in order to help compute scene lighting.[17]
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.[18]: 176
Microtexture
An alternative term sometimes used for Detail textures.
The clipping of 3D rendering primitives against the near clip plane. Necessary to correctly display rendering primitives that partially pass behind the camera.
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.
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.
A small integer holding a bit for the result of every plane test (or clip window edge test) failed in clipping. Primitives may be trivially rejected if the bitwise AND of all its vertices outcodes is non zero
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.
Premultiplied alpha
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: dst *= (1 - alpha) + src; capable of mixing alpha blending with additive blending effects
Primitive
A basic unit of geometry for rendering or modelling.
A texture map applied with wrap-round UV coordinates extending between the 0–1 range (representing one unit of the image), exhibiting periodicity. Contrasts with clamped, mirrored modes or unique mappings.
Resource
Data (often held in a buffer managed by a rendering API) read by a graphics pipeline, e.g. texture maps, vertex buffers, shaders, index buffers, or other pieces of 3D model data.
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.[29]
In shading, specular highlight is a bright highlight caused by specular 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.
2D image moving on the screen, with potential partial transparency and/or animation.[3]: 550
State changes
The passing of changes in render states in a graphics pipeline, incurring a performance overhead. This overhead is typically minimised by scene sorting.
A buffer storing an integer value for each according screen pixel, used e.g. to mask out specific operations and achieve specific effects.
Stereo rendering
Rendering the view twice separately for each eye in order to present depth.
Surface normal vector
In shading calculations, the normal to a 3D model surface, typically compared with the light and view vectors to compute the resulting visible colour. Also used for displacement mapping.
The process of ordering triangle primitive vertices, calculating signed triangle area and parameter gradients between vertex attributes as a prerequisite for rasterization.[33]
Rejecting a rendering primitive or 3D model based on a cheap calculation performed early in a graphics pipeline, (e.g. using outcodes in clipping). The opposite of trivial accept.
Graphics represented as a set of geometrical primitives.
Vector maths library
A library defining mathematical operations on vector spaces used in 3D graphics, concentrating on 3D and 4D vectors, and 4x4 matrices, often with optimised SIMD implementations.[38]
A rendering resource managed by a rendering API holding vertex data. May be connected by primitive indices to assemble rendering primitives such as triangle strips. Also known as a Vertex buffer object in OpenGL.
A truncated pyramid enclosing the subset of 3D space that projects onto a 'viewport' (a rectangular region in screen space, usually the entire screen).
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.
High-performance, low-level graphics API by Khronos Group.
W
W buffering
A depth buffer storing inverse depth values, which has some advantages for interpolation and precision scaling.
Weight map
A set of Vertex attributes controlling deformation of a 3D model during skeletal animation. Per-vertexweights are assigned to control the influence of multiple bones (achieved by interpolating the transformations from each).[39]
^Heckbert, Paul; Hanrahan, Pat (1984). "Beam Tracing Polygonal Objects". Proceedings of the 11th annual conference on Computer graphics and interactive techniques - SIGGRAPH '84. pp. 119–127. doi:10.1145/800031.808588. ISBN 0897911385. S2CID2845686.