Game Development Reference
In-Depth Information
use normal maps to increase the topological detail of the object without add-
ing extra polygons, but you should use at least high-quality diffuse maps with a
greater amount of detail painted in. More information about these maps is out-
lined in the “Painting 3D Images” section of this chapter.
As examples, a game like
Gears of War
might create a very high-resolution
model in a program like ZBrush and then export normal maps to be used on
a lower-resolution version of the model.
World of Warcraft
uses a much lower
polygon mesh and paints the details into the diffuse map.
Gears of War
also
uses diffuse maps in conjunction with the normal maps to allow the greatest
amount of detail while keeping the poly count manageable. Most modern games
use the normal/diffuse map combination.
Texture-map size is often determined more by the power of the graphics hard-
ware; it isn't as much a consideration for a low frame rate (although it does have
an impact). The number of polygons moving around, and any special effects
going off, are the first targets of poor frame rate.
Main characters in games tend to have about 3000-4000 polys; however,
depending on the platform the game is designed to run on, that number can
vary a great deal. Figure 5.10 shows a completed character model from Artery
diffuse maps are
sometimes referred
to as
skins
.
FiGuRe 5.10
Artery Studios specializes in creating models for all types of projects.
This model, an example of a character for a game, was created using a low poly count. The
polygons are visible in the figure at far left. The skin was painted with greater detail to make
the figure appear more realistic.
