3D Dictionary
Alpha blending
Combining two images with different
transparency levels so that one image appears visible through the
other. An object's transparency is defined as its Alpha value or
Alpha level.
The removal of artifacts from an image.
A combination of four colors in a single 3D
image used to improve that image's resolution.
Removal of any image displayed outside of a
predefined shape.
Changing the color and brightness of a 3D image
as it moves relative to the viewer. Color becomes less bright as
the image moves away, brighter as it moves closer.
Substituting combinations of colors you do have
for colors that you don't. For example, if your computer is only
capable of displaying 256 colors and you load an image that use
65,000 colors, your computer will create substitutes for the
colors you don't have by combining the colors that you do. The
color quality of a dithered image is inferior to a non-dithered
image.
A way for your computer to work on an image two
different ways at once. Before displaying an image, your video
card calculates what a finished image will look like and displays
that image while it is calculating the next image in a video
stream. Double buffering affords smoother playback for video or
any other multiple-frame file format.
A measurement of how often information in a
video or animation file is updated on your screen or how many
frames of motion you see in a given second. Movies and television
are shown at 24 fps.
Overlaying a photo image on a 3D object so that
the photo takes the shape of the object.
Transformation of a 2D object into a 3D object.
A way of rendering an image. The computer
computes the path of a light ray from the light source to the
objects (from which the ray reflects), and further to the
observer. It does this for every pixel on the monitor. This is a
very intensive calculation, but the results are worth it.
Bending of light when it passes through another
substance.
Converting a graphics image into an array of
pixel colors for the display.
Both shading methods make the surface and color
of an object appear smoother. Phong shading takes more CPU time
but gives better results. Gouraud shading is faster.
Overlaying a graphics image on a 3D object, so
that the photo takes the shape of that object.
An image that can partially be seen through.
The texture map is stored at several levels of
detail in a structure called a mip map. You compute the texture
coordinates and the exact level of detail. This gives you the two
closest levels of detail available in the mip map. In each one
you perform a bilinear interpolation, and then a linear
interpolation between the two levels (that's why it's called
tri-linear). High-end graphics workstations (like SGI
RealityEngine) use trilinear mip mapping.
A point which marks the intersection of two or
more edges of a polygon or other graphics object.
The same as texture mapping. In the case of
video mapping, the texture is applied to an animation or a video
clip.
A two-dimensional array made up of a grid of
points on a sea-level plane, each containing the value of the
depth (z) at that point. In this way, every pixel on the monitor
has a "depth value" so that the program knows which
polygons are in the foreground and which are in the background.