Game Development Reference
Fig 1.9 A 3D model constructed from
triangles in Blender.
The wireframe model that represents a 3D object is called a mesh . The
number of polygons in a mesh is called the polycount . The higher the
polycount, the more triangles in the model and the more computer
processing power required to render and manipulate the model. For this
reason, computer game artists must find a balance between functionality
and visual quality, as a high-resolution model is too costly with respect to
making the game run slowly. The models must be dynamically processed
and rendered in real time. In contrast, animated movie models can be much
higher quality, as they are not rendered in real time. Next time you are
playing a game, take a closer look at how the models are constructed.
Direction is the orientation of a line. Depending on its treatment, it can
imply speed and motion. A line can sit horizontal, vertical, or oblique. In
computer graphics, physics, engineering, and mathematics, a Euclidean
vector is used to specify direction. A vector stores information about how
to get from one point in space to another in a straight line. Not only does
it represent a direction, but also a distance, otherwise called its magnitude .
The magnitude of a vector is taken from its length. Two vectors can
point in the same direction but have different magnitudes, as shown in
Figure 1.10a . In addition, two vectors can have the same magnitude but
different direction, as shown in Figure 1.10b . A vector with a magnitude of
one is normalized .