10World
Space
The virtual world itself needs to be defined in a 'world space'. By its nature
as a computer simulation, this world is necessarily limited. The computer must
put a numeric value on the locations of each point of each object within the
world. Usually these 'coordinates' are expressed in Cartesian dimensions of X,
Y, and Z (length, height, depth). It is possible to use alternative coordinate
systems such as spherical but Cartesian coordinates are the norm for almost all
applications. Conversions between coordinate systems are fairly simple (if time
consuming).
10.1. World
Coordinates
A major limitation on the world space is the type of numbers used for the
coordinates. Some worlds use floating point coordinates. This allows a very
large range of numbers to be specified, with some precision lost on large
numbers. Other systems used fixed point coordinates, which provides uniform
precision on a more limited range of values. The choice of fixed versus
floating point is often based on speed as well as the desire for a uniform
coordinate field.
One method of dealing with the limitations on the world coordinate space is to
divide a virtual world up into multiple worlds and provide a means of
transiting between the worlds. This allows fewer objects to be computed both
for scripts and for rendering. There should be multiple stages (aka rooms,
areas, zones, worlds, multiverses, etc.) and a way to move between them
(Portals).