Game Development Reference
In-Depth Information
Everything in the game has to react to light. Every polygon not only needs to have a
texture, it has to have lighting. Many games have multiple light sources and dynamic
lighting that moves during the game. So not only does the game system have to
track lighting on a polygon from one light source, it also has to calculate the effect
of multiple light source effects on all polygons. But even then we still are not done.
At any given time in the course of the game, there is a significant chance that the
view will change and elements in the view will be in motion. In other words, the
game system has to track and calculate the new positions of all the vertices, poly-
gons, textures, and lighting every frame. In addition, some elements are animating
or moving independently of the view. Not only does the game system have to track
where the moving objects are within the view, it also has to actually calculate those
movements via the game AI as it reacts to whatever the player's input might be. Are
you still with me?
All these game calculations have to be completed 60 times every second. Once
everything is calculated, the scene can then be rendered to the display. Okay, let's
think about the display, which is made up of individual pixels. During the render-
ing process every individual pixel has to be given information on brightness and
color. If a game is running at 1024
×
768 resolution, it means that for every frame,
brightness and color information has to be delivered to 786,432 individual pixels.
That is more than 47 million deliveries every second of the game.
Are you beginning to see why 3D games are so complex? Can you see why a very
powerful computer system is required to run 3D games?
Why is this so important to the artist? Well, understanding what it takes to display
even a single frame of a 3D game will help you to plan and execute your art in such
a way that you will be able to get the most out of the game you are creating.
Because even the most powerful game systems have a limit on the number of cal-
culations they can process at any given time, you have to set limits on the number
of polygons, textures, lights, and animation processes. Sometimes these limits may
vary. For example, you might have a need for a lot of specialized lights in a particular
part of your game. To keep the frames running smoothly, you can reduce the num-
ber of polygons and textures in that area. Figure 1.20 shows the steps in the process
of displaying a 3D game.
I think it is important for you to understand that this is only an overview of what
it takes to run a 3D game. The entire process is actually much more complex. We
haven't even covered things such as particle effects and physics models. The pur-
pose of this whole chapter is to help you get a feel for the complexity and overall
scope of creating a 3D game.
