Datasheet

When scaled, vector graphics do not suffer from the same limitations as raster images.
As you can see in Figure 1.2, vectors can be scaled with no loss of quality; they will never
pixelate.
Motion in vector programs is stored not by a long sequence of image files, but through
changes in positions of the geometry and in the math that defines the shapes and volumes.
When a Flash cartoon is played on a website, for example, the information downloaded
and fed into your computer is in vector form. It contains the position, size, and shapes
of all the characters and backgrounds of the animation.
Your computer then renders this information on-the-fly,
in real time, into a raster display that you can enjoy on
your screen.
In Maya, however, you work with vectors that are dis-
played as wireframes. When you finish your scene, Maya
renders the image, converting the vector information into
a sequence of raster images.
When a vector file is edited, its geometric information
is altered through the tools of the vector program. This
allows for easy manipulation and handling of changes
and is perfect for design industries in which collaboration
and efficiency in changes are a necessity. Only when the
editing is finished will the vector file be rendered into a
new sequence of raster images by the computer.
Image Output
When you’re done with your animation, you’ll want as many people as possible to see it;
to make that happen, you have to render it out into a file sequence or a movie file. The file
can be saved in any number of ways, depending on how you intend it to be viewed.
COLOR DEPTH
An image file stores the color of each pixel as three values, representing red, green, and
blue. Image type depends on how much storage is allotted to each pixel (the color depth).
These are the color depths common to image files in CG production:
Grayscale The image is black and white with varying degrees of gray in between, typically
256. Grayscale images are good for rendering out black-and-white subjects; no extraneous
color information is stored in the image file.
16-Bit Color Display or High Color – 5-Bit Image File Each color channel (red, green, blue)
gets 5 bits of space to store its value, resulting in an image that can display a maximum of
32,768 colors. Each color channel has a limited range of shades but still gives a nice color
image. You might notice the gradation in the different shades of each color that can result
in color banding in the image.
14 chapter 1: Introduction to Computer Graphics and 3D
Figure 1.2
A vector image at its
original size (left)
and blown up to 200
percent (right)
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