Glossary » Computer Graphics

algorithm animation

algorithms are the formal procedures for performing some computational task, such as the procedure to sort a set of numbers. An algorithm animation is a graphical display of process over time (auditory cues are also quite common). Algorithm animations are…

antialiasing

drawing graphics with smooth blends of colors along edges to avoid sudden shifts of color between pixels and give a smoother appearance. When a line is drawn on a computer screen, the common way to draw it in the early…

anticipation

in animation, preparation before an action so that the user has some foreshadowing of the action and can more effectively interpret the action. For instance, when a character runs away, the character will back off slightly in the opposite direction…

bat

a flying mouse; an input device that permits pointing to objects in 3-dimensional space by moving the bat around in the air, similar in spirit to the use of a mouse to point to objects in 2-dimensional space.

binocular display

also stereoscopic display; a display that is composed of 2 separate displays which are directed separately to the left and right eyes. The viewpoint is slightly different for each, reflecting the slightly different view each eye would have when embedded…

bit depth

the number of bits used to represent the color of an individual pixel on a computer screen. A bit depth of 1 would represent that the pixel could only be on-off — a black-and-white display. 8-bit displays can display 256…

cone tree

a way of displaying hierarchical data (such as org charts or directory structures) in 3 dimensions. Branches from any node are spread out in a cone. This allows a denser layout than traditional 2-dimensional diagrams, though nodes may be obscured.…

dataglove

a glove with sensors to detect hand position and orientation, and finger position, used to provide 3-dimensional input, especially in virtual reality (VR) systems.

declarative graphics system

software system to support the drawing of graphics through specifying the graphic objects that exist and their properties without having to specifically instruct the computer to draw at any specific time, in contrast to procedural graphics where each drawing command…

depth perception

the experience of perceiving a third dimension of depth into a computer screen. For instance, windows add a certain depth by having shadows, and buttons indicate their dimensionality by having beveled edges.

Many different graphical qualities can act as depth…

dome tree

like a disk tree, a representation of hierarchical information with the primary node at the center and each successive descendant falling on concentric rings spanning out from the center along a 3-dimensional dome. The dome allows relationships to be indicated…

drag handle

a small box on the edge of a selected object that can be dragged to move the object.

egocentric viewpoint

a virtual reality or immersive environment that is displayed into a person, by projecting it directly to a person’s senses with, for instance, a head-mounted display and headphones, as opposed to displaying the environment onto screens external to the person.…

exocentric viewpoint

a virtual reality or immersive environment that is displayed around a person, for instance, by projecting scenes onto adjacent walls, rather than displaying it directly to someone’s senses (e.g. with a head-mounted display).

follow through and overlapping action

in animation, certain parts of an animation must keep moving even after the main action has completed, e.g. when a woman swings her head, her hair continues moving after she stops moving her head, and this hair motion may continue…

frame rate

the speed that an animation or video is displayed, specifically: the number of frames (individual pictures making up the animation or video) that are displayed per unit time. For instance, televisions display 60 frames per second (also called the “refresh…

ghosting

making an item fade when it is disabled (as when menu items are dimmed when they are currently unavailable); usually called dimming. An uncommon term, not to be confused with ghost indicators.

gnomon

a miniature view of the principal axes in a 3D coordinate system used to indicate the orientation of the current view in a 3D graphics system. (originally referred to the shadow of the pointer on a sundial)

grab handles

also called hotspot, birdie, or handle; small boxes on the edge of a selected object that can be grabbed and moved to drag or resize the object (or sometimes perform another manipulation, such as rotating the object).

grid

(graphic design) a system of templates used as a framework to create a document with uniform layouts between pages while still allowing each page to adapt to its content. The grid defines positions for standard elements on the page, margins,…

halo effect

(graphics) the glow that appears around an antialiased image when it is placed over a background color that is different from the background used when making it antialiased. This occurs for gif images, which allow transparency, but only for an…

head-mounted display

HMD; a computer monitor or other display (such as an LED readout) that can be worn on the head so that a user can view it without looking away from the surrounding environment and without having to hold the display,…

hotspot

the sensitive region of an image, such as the areas that are clickable on an imagemap displayed on a website, or the position on a pointer icon that indicates the exact point that is being pointed at.

icon

in computer terminology (as opposed to graphic design terminology), an icon is a small image used most often to represent files or label a button. Much discussion goes into how icons should be designed: the use of line, color, and…

immersive interfaces

an interface that heavily involves users by bringing them into the world of the interface both conceptually and perceptually, as in virtual reality, e.g. by surrounding their visual senses (as with VR glasses), giving them stereo sound, and providing an…