43310.1.4. The Virtual Camera
In computer graphics, the virtual camera is much simpler than a real camera
or the human eye. We treat the camera as an ideal focal point with a rectangu-
lar virtual sensing surface called the imaging rectangle fl oating some small dis-
tance in front of it. The imaging rectangle consists of a grid of square or rect-
angular virtual light sensors, each corresponding to a single pixel on-screen.
Rendering can be thought of as the process of determining what color and
intensity of light would be recorded by each of these virtual sensors.
10.1.4.1. View Space
The focal point of the virtual camera is the origin of a 3D coordinate system
known as view space or camera space. The camera usually “looks” down the
positive or negative z-axis in view space, with y up and x to the left or right.
Typical left - and right-handed view space axes are illustrated in Figure 10.30.
Figure 10.29. The fl ashlight in Luigi’s Mansion is composed of numerous visual effects, in-
cluding a cone of translucent geometry for the beam, a dynamic spot light to cast light into
the scene, an emissive texture on the lens, and camera-facing cards for the lens fl are.
Right-Handed Left-HandedVirtual Screen ScreenVirtualFrustum FrustumxCzCyCxC
zCyCFigure 10.30. Left- and right-handed camera space axes.
10.1. Foundations of Depth-Buffered Triangle Rasterization