Game Development Reference
In-Depth Information
Character modeling is a complex process requiring a great deal of time and skill.
The character modeler is creating a complex model that needs to be able to look
good and move correctly. He also needs to build the model with as few polygons
as possible. Although game systems are continuing to become more and more
powerful, they are still limited. The limitations on the systems require the game
artist to work within a polygon budget for each character.
A
polygon budget
is a limit on the number of polygons that an artist can devote to
building a character. As a beginner you need to understand the importance of a
polygon budget. Polygon budgets are created by taking the total processing power
of the game system and dividing it among the processing needs of the game. For
example, a racing game might have the following processing needs.
Game AI
■
Physics model for cars
■
Audio
■
Graphics
■
Graphics are just one of the elements that requires processing. Within the realm of
graphics are several different processing requirements.
Animation systems
■
World geometry
■
Textures
■
Character (automobile) geometry
■
Special effects
■
After the total processing requirements for each facet of the game are determined,
you can calculate the initial polygon budget. For example, suppose that in creating
an adventure game, the portion of processing allocated to characters is 10 percent
of the total processing power. If the game system can render 500,000 textured
polygons per frame, then the polygon budget for characters will be 50,000 poly-
gons. That isn't 50,000 polygons per character; rather, it is 50,000 polygons for all
characters that will ever be on screen at the same time. Thus, if the game limits the
number of onscreen characters to 10, then the budget for individual characters
