Ultimate Game Design : Building game worlds

to see the seams along their adjoining edges. If we were tiling a snow surface, for instance,
we wouldn’t want to see tile-edge lines where the tiles mesh against each other.
Textures that can tile are textures that fit together like jigsaw pieces along their
own edges. Figure 3-6 shows an example of a “tile-able” texture. This type of texture
might be used as a floor surface or a wall surface.
Other kinds of textures are more use-specific and are not used to fill large, open
spaces like floors or walls. They tend to be used to imply physical environmental details
like sewer outlets, stained-glass windows, or piping systems. Figure 3-7 shows
an example of a use-specific texture.
Depending on the scale system you are using, textures can be created at different
pixel sizes, resolutions, and bit depths. Each of these is determined by your game engine’s
requirements. Each game engine is custom-written to handle surface or texture
information (sometimes in new and ever-changing ways). Quite commonly, however,
most handle only textures of specific sizes and resolutions.
For instance, repeatable textures created to cover large surface spaces like walls
and floors might be created at 128×128 (128 pixels wide by 128 pixels high). A “detailing”
texture like a door trim pattern, a texture that would fit nicely surrounding
doorway edges, might be created at 64×64. Determining the appropriate size for
your textures is usually a matter of intended use. Knowing how a texture will be used
in a scene is an important consideration when constructing it.
FIGURE 3-6
Tile-ready texture
C H A P T E R 3
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Lighting, Texturing, Particles, Effects, and Audio