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Landclass In FS2004
As you already know, FS2004 covers the entire Earth. You can fly anywhere and get a pretty good representation of the
types of vegetation and urban sprawl appropriate for the region you are in.
In order to do this efficiently, Microsoft came up with a clever way of representing the entire globe using what they call
landclass. The FS2004 landclass system is based on a grid of 1km x 1km squares, which cover the entire Earth.
These 1km x 1km squares are called LOD13 cells by developers. Each one of these 1km x 1km squares has a
particular value assigned to it, that tells FS2004 which available texture, from a list of possible textures, is appropriate to
be displayed for that 1km x 1km square area. For example, a value of 121, tells FS2004 to use a texture that
represents a busy urban area with hi-rise structures.
The landclass system does a very good job of representing the Earth in FS2004, without taking up an excessive amount
of resources (RAM and disk storage). At this point in time, it is not possible to cover the entire earth using photographic
textures. Even if the photographic textures were available for the entire earth, the disk storage would exceed that of
even the most powerful PC system today.