Glossary

Aliasing: It is so-defined the "terracing" effect that occurs when dealing with digital images. The two main aliasing artifacts are edge aliasing and texture aliasing.
Edge aliasing happens at edges of models most often and can be described as edge "crawling". It gives the appearance of stepping "sliding" up and down the edge of models.
Texture aliasing can be described as "shimmering" or "sparkling". This tends to be particularly problematic in simulation games as they tend to have less then optimal mip mapping to deal with texture aliasing using more simplistic methods.
top
Bus mastering: Bus mastering is an enhancement that allows the video card to take over the system bus (if it supports bus mastering) so that the video card can perform transfers to and from system memory directly. This improves performance on certain video operations, particularly 3D acceleration functions that use the system memory. Most video operations work on the video card's own memory and therefore don't benefit from bus mastering.
top
CPU: It stands for Central Processing Unit, which is the "heart" of the PC. CPUs used in home PCs use the x86 architecture, defined by Intel in 1980 (when the first 8086 was launched), with its 32-bit extensions IA-32.
top
Frame buffer:This is the place where the information is stored about the video image itself. Each pixel on the screen has associated with it typically 4 to 32 bits of data that represent its color and intensity and for this reason the dimension of the frame buffer defines the maximum resolution and color depth. At each change of frame this area is totally reset and refreshed. The video processor (along with the system CPU) manipulate this data to change the screen image and the RAMDAC reads it and sends it to the monitor.
top
FSB: It is the system bus, which connects the CPU to the North Bridge. Its bandwidth is calculated as (width * frequency) and defines the maximum quantity of data the CPU can send or receive from the rest of the PC.
top
Interpolation: Mathematical-statistical process at the basis of many graphical techniques. It consists of building a function among two or more known values.
top
Lightmaps: It is a semitransparent texture, in which is premapped the desired effect of light which we want to obtain on another texture. It is applied using as alpha channel white or another preselected color.
top
LOD: Referred to Mip Mapping, it shows the number of version used of the same texture. The higher it is, the better the visual quality and the sharpness of texture should be, but the higher will be the bandwith occupation. Generally there is no necessity of increase this value, but when using Antialiasing it can help in compensating the fuzziness caused by the FSAA, making the textures sharp anyway.
top
Mip-mapping: Texturing technique which uses several copies of the same texture at different resolutions, in order to use the one that best fits to the dimensions of the treated surface. The number of version of the texture indicates the LOD.
top
Multitexturing: Application of more than one texture to the same object; we can tell of single-pass multitexturing if the video card hardware is able to dp this work in one clock cycle; this happens if the number of texture units per pipeline is al least equal to the number of the overlapped textures in the selected mode.
top
North Bridge: One of the two chips which constitute the chipset. It contains the system memory controller and allows the CPU to access to the AGP port, the system RAM and the South Bridge (and thus to all ISA/PCI devices).
top
PCB: It is the green plastic material which is the physical base for all circuits. It must have good mechanical and thermal behavior and an excellend electromagnetic behavior, since EM interferences must be as low as possible (ideally 0). With a poor quality PCB, the board will reach very low clock frequencies.
top
Rendering: Second phase of the generation of a 3D image. Once defined the polygons, the materials and the lighting, the rendering takes care of all operations needed to create a bitmap image. In this phase textures are applied and processed. There are several rendering techniques, like gouraud, phong , raytrace or radiosity; the more realistic we want the scene, the higher will be the time, memory and computing power needed.
top
Texel:Texture Element, the basic element, the pixel which form a texture
top
Texture: For realistic objects, it is necessary to overlay pictures on them to give them texture. For example, most walls are not made of a solid, flat substance. They are made of a material such as brick, wood or plaster, and they may have pictures, tapestry or signs on them. Texture mapping allows objects to be made so that they appear to have substance instead of being "flat". There are in fact several different types of texture mapping that are used by various software and hardware
top