Chapter 4 Perspective, Scene Design, and Basic Animation 103
in pixels. For example, if the computer monitor setting is set to 1280 × 780
resolution, a designer must create a frame that is 1280 pixels wide and 780
pixels high to fi ll the screen. If a game frame is set larger than the screen
size, some images may not show. If that happens, a designer might need
to modify the screen settings to fi t or allow the game frame to scroll. If the
frame scrolls, it moves with respect to the character, Figure 4-13.
Visible screen
Figure 4-13. This is how a scrolling map is shown on screen. All sections of the map are active and will continue to have
active objects in motion even when not displayed. As the player moves, the camera centers the player on the map. Large
maps with continuing action off screen take a lot of computing power to keep the game running smoothly.
CASE STUDY:
DIGITAL COLOR MODELS
To create the millions of colors we see in
real life, computers need to mix basic colors.
In Chapter 1, you saw how the color wheel
allows you to mix the three primary colors (red,
blue, and yellow) to create the complementary
and contrasting colors. Digital color models
are similar, but slightly different. Two common
digital color models are RGB and HLS.
The RGB, or red, green, blue, model
combines three colors in different densities to
create different colors. The RGB color model
is used on most personal computers, television
sets, LCDs, and handheld devices. These
display screens can easily blend the three
color components to create white, black, and
millions of colors in between. The bit depth of
the color (8 bit, 16 bit, 32 bit, etc.) determines
the number of colors that can be created.
In the RGB model, a color value of 0,0,0
(red = 0, green = 0, blue = 0) is black, as shown
in the fi gure. This makes black the base color
for the RGB model. So starting with black,
when you add red, blue, or green in different
densities (values), new colors are created. If you
add a maximum amount of red, green, and blue
(255,255,255), the color is white. The maximum
amount of color that can be added is 255. Every
digital color can be written in RGB format.
(Continued)
Target
RGB
values
Color is
black
This is the Colors dialog box from a Microsoft Offi ce
application. In this example, the RGB color model is used to
defi ne black.