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Diamond Viper V770 Ultra Review
3D Glossary
This page provides definitions for the some of the 3D graphics terms that were used in this review.
Accelerated Graphics Port (AGP) 4X
The latest generation of Intel's bus technology specifically designed for 3D rendering. System memory is utilized to process complex 3D images, thereby allowing for faster graphics processing. AGP 4X allows for a peak bandwidth over 1 gigabyte/sec, twice that of AGP 2X.
Anti-Aliasing
A technique to reduce jagged edges ("jaggies") of polygons and lines. Pixels on either side of edges are rendered as a blend of the adjoining colors to smooth the appearance of the edge.
Alpha Blending
Alpha blending is a method that utilizes an alpha channel that denotes the transparency or opacity of a pixel. By using this value, realistic rendering of translucent or transparent surfaces such as glass, water, or fog is possible. As well, this technique can be used to blend two textures on top of one another, without totally hiding either texture.
Anisotropic Filtering
Advanced filtering technique that addresses quadrilateral shaped and angled areas of a texture image. A sharper image is accomplished by interpolating and filtering multiple samples from one or more mip-maps to better approximate very distorted textures. This is the next level of filtering after trilinear filtering.
Bump Mapping
An effect such as adding a raised, 3D tactile texture to a map, which increased the realism of 3D objects. Examples of this might include a final rendered image of a brick wall that shows the uneven surface of the brick and the grooves between bricks.
Double Buffering
This is the process of using two frame buffers for smooth animation. While the image of the first buffer is being displayed, the graphics controller can use the second buffer to build or render the next image. Once the second image is completed, the buffers are switched. Thus, the result is the appearance of smooth animation because only complete images are displayed, and the process of drawing is not shown.
DirectX
A application programming interface (API) standard the Microsoft developed to increase multimedia performance of the PC with sub-related standards (e.g. Direct3D, DirectSound, DirectDraw, etc.) for 3D graphics, sound, and video.
Gouraud Shading
Gouraud shading is a method in which the triangle color is obtained by interpolating the vertex colors that are located at each corner of the triangle. By utilizing this technique, 3D objects appear increasingly realistic due to the smooth, curved appearance of the surfaces, even though they consist of many seperate polygons.
Hardware Triangle Setup
A 100% hardware triangle setup engine allows drivers to pass polygons directly to the rendering portion of the 3D graphics processor without forcing the CPU to pre-process these polygons. By moving this function from the CPU to the graphics chip, increased performance is realized to achieve stunning interactive 3D.
Mip Mapping
Mip is actually an abbreviation for the Latin phrase Multum in Parvum, which means "many in one". Basically this is a technique to increase quality whereby scaled versions of the original texture image are generated and stored. These stored images are then used in rendering a 3D scene depending on their size and depth, which provides the best quality.
On-Chip Cache
Memory on the graphics chip designed to store textures, greatly enhancing 3D rendering performance. Memory that is integrated into the graphics chip is much faster than memory on the graphics card.
OpenGL
OpenGL is a 3D graphics API, originally developed by Silicon Graphics, Inc. which is now available for use on the Windows platform. For PC 3D graphics accelerators, there are two ways to implement OpenGL support, a full Installable Client Driver (ICD) or a Mini Client Driver (MCD). ICD is the original driver model for OpenGL, and enables vendors to access the entire OpenGL pipeline, allowing them to increase acceleration while maintaining the stability and compatibilty of the driver. MCD is a stripped down OpenGL driver, allowing access to only a portion of the OpenGL pipeline, limiting the ability to increase performance and stabilize the driver.
Perspective Correction
By using a computational intensive method, this particular way of doing texture mapping provides a increased realistic image. Perspective correction takes into account the depth of a scene while rendering texels onto the surface of polygons. This provides the appearance that object nearer the viewer are larger and objects that are further appear smaller. In addition, this allows parallel lines such as railroad tracks converge in the far distance.
Pipelining
AGP graphics boards can queue multiple commands using a method call pipelining. In pipelining, AGP overlaps the memory or bus speed times for a request with the issuing of following requests. In the PCI bus, the second request does not begin until the data transfer of the first request finishes.
SDRAM
Synchronous Dynamic Random Access Memory (SDRAM) is an extremely fast form of graphics memory that incorporates a pipelined architecture which helps to set up synchronization between itself and the CPU bus clock for very high memory access speeds. Increased performance is obtained with SDRAM by using a multiple bank architecture that simulates the dual port nature of other video RAM technologies.
Sideband Signaling
An extra 8-bits of addressing capability built into AGP which, in effect, allows the AGP graphics board to request information over AGP at the same time as it is receiving data over the 32-bit datapath of the bus. This is yet another way that AGP graphics boards can create better efficiencies and improve overall graphics performance.
Single-Pass Multi-Texturing
A feature made possible by new advanced 3D graphics processors such as the NVIDIA RIVA TNT2. In order to provide increased realism in 3D worlds, multi-texturing is the process by which multiple texture maps are rendered and blended together. An example of this might be a rendered image of yourself looking into a chrome hubcap and seeing your reflection. Traditionally 3D graphics processors were able to utilize this feature by using two passes. First rendering one image, then the other and finally blending them. The action whereby a 3D graphics board processes these two images in one pass is considered single-pass multi-texturing. As you might imagine, this provides for increased performance and realism while maintaing visual quality.
Stencil Buffer
This buffer holds special information for each pixel as to whether or not to draw it. Stencils can be of any shape and can be thought of as cuts the allow an image to be seen through the cutout. This feature is particularly useful in creating special effects such as shadowing from multiple light sources.
Texture Mapping
The process of overlaying stored 2D pictures or bitmaps onto a 3D polygon that creates an increased visually realistic representation of the object in 3D space. This is one of the most common techniques for displaying realistic 3D objects.
TwiN Texel 32-bit Graphics Pipeline
This twin-engine design consists of twin processors that incorporate both an advanced floating point setup engine coupled to a pixel processor, in addition to the additional lighting and special effects processors. In addition, all operations within this pipeling are now rendered in 32-bit. By providing two 3D pipelines rendering at 32-bits within a single-chip, increased super high rendering is achievable with the utmost quality to achieve visually stunning interactive 3D.
Trilinear Filtering
A filtering technique which interploates bilinearly filter samples from two mip-maps. Trilinear mip-mapping prevents moving objects from displaying a distracting "sparkle" caused by abrupt transitions between mipmaps resulting in a smoother graphics image.
True 128-bit
A true 128-bit graphics subsystem incorporates both a 128-bit internal graphics engine in addition to a 128-bit path from the controller to the graphics memory. Graphics boards based on this technology provide enhanced 2D and 3D performance in comparison to the older 64-bit technology.
Z-buffer
An additional portion of memory which stores a 3D object's value on the Z-axis (depth). The graphic controller can decide to draw or delete certain lines by constantly comparing Z-values in this buffer, and therefore make certain parts visible or hidden to the viewer.
Next: Appendix
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Last Updated on September 4, 1999
All trademarks used are properties of their respective owners.
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