When build 3D symbolic models, it should be taken two
factors into account firstly. One is that all kinds of the spatial
feature information are suitable for 3D symbolic model to
describe. The other is that 3D symbolic model itself is realizable from the computer graphics and visualized
representation point of view, i.e. the spatial feature has
information of general physical elements of geographic object,
and it is difficult to represent by 2D symbol but is convenient
for 3D symbol. For some abstract symbols, it is not suitable to
be represented by using 3D symbolic models, while can be
displayed by using models with dynamic and animation mode.
When designing 3D map symbol model, it should take the
symbol’s artistry and readability into account, as well as
symbol’s feasibility. Only all aspects are considered, the
system performance would be optimized deeply. Because the
symbol’s represent environments are different between 3D GIS
and 2D map, the general design principles and requirements are
different [3]. Some points below should be followed.