3DLABS Permedia3 - Manual (Page 31)

Terms and Definitions
Appendix B - Glossary 24
Dithering
The process of converting an image with a certain bit depth to one with a lower bit depth.
Dithering enables the application to convert an image’s colors that it cannot display into two
or more colors that closely resemble the original. Dithering works because the mind is tricked
by the pattern of colors into thinking it’s a different color.
Double Buffering
With double-buffering, images are rendered in the back buffer and then displayed on the
screen once the drawing is completed. This results in the smooth, flicker-free rotation and
animation of 3D models and scenes.
Driver
A driver is a special interface program that is developed to perform the communication
between the application program, the device (i.e., graphics peripheral) and the operating
system.
EVGA
Extended Video Graphics Array. EVGA runs at 1024 x 768.
Flat Shading
The simplest method of shading. Each triangle is assigned one single color, resulting in a
faceted appearance of the surface.
Floating Point
The portion of the mathematics execution unit of a processor generally associated with
multiply and divide operations.
Frame Buffer
A 24-bit, true-color frame buffer provides 8 bits for each red, green and blue primary display
color. This results in 16.8 million color combinations. A second, or double, buffer enables
system to calculate pixels one step ahead of the screen display for smooth, distortion free
images.
Gamma
A curve representing both the contrast and brightness of an image. Changing the shape of the
curve changes the RGB color output.
Geometry
The intermediate stage of the 3D pipeline, geometry determines the location of the object and
the frame of reference of the viewer in relation to the object.
Gouraud Shading
This method of shading, more complex than flat shading, shows subtle color changes across
an object. Gouraud Shading is accomplished by adding pixels in a graduated scale of colors.
Graphics Accelerator Card
A graphics accelerator performs 3D functions in the hardware, thereby relieving the CPU of
repetitive, complex and intensive calls. This results in enhanced performance and speed.
Heidi
The API developed by Autodesk to work with its products, such as 3D Studio MAX and
AutoCAD.