Mathematical Topics from 3D Graphics - 3D Math Primer for Graphics and Game Development - page 362

have a much more di cult time understanding even the global illumination
techniques of today, much less those of tomorrow.

10.2 Viewing in 3D

Before we render a scene, we must pick a camera and a window. That is,
we must decide where to render it from (the view position, orientation, and
zoom) and where to render it to (the rectangle on the screen). The output
window is the simpler of the two, and so we will discuss it first.
Section 10.2.1 describes how to specify the output window. Section 10.2.2
discusses the pixel aspect ratio. Section 10.2.3 introduces the view frustum.
Section 10.2.4 describes field of view angles and zoom.

10.2.1 Specifying the Output Window

We don't have to render our image to the entire screen. For example, in
split-screen multiplayer games, each player is given a portion of the screen.
The output window refers to the portion of the output device where our
image will be rendered. This is shown in Figure 10.2.

Figure 10.2. Specifying the output window