Graphics Programs Reference
In-Depth Information
Figure 2.2
The diferent types of
shapes based on dimensions. The dot
in (a) includes zero dimensions; the
line in (b) includes one dimension;
the shapes in (c) include two
dimensions; and the shapes in
(d) include three dimensions, or X, Y,
and Z.
(a)
(b)
(c)
(d)
Perspective
The concept of
perspective
is associated with how the eyes see things in
the 3D space and the volume of the objects. When you look at objects
and landscapes, you notice that the farther things are from you, the
smaller they appear to the eye. For example, if you look at railroad
tracks going through the landscape, you will notice that they look like the
space between them is getting smaller, until it vanishes in the horizon
(Figure 2.3).
This trick is known as the
vanishing point
—the point at which parallel lines
converge or disappear. In the 3D world, when you view an object or create a
camera to view an object, you can notice that the sides of the object are
