Geography Reference
In-Depth Information
Fig. 2 3D visualization of Faculty of Science campus on Kotl´ˇsk´ street in web browser
buildings, rooms and routes. Synchronization between CityGML and IndoorGML
will be implemented through XLink technology (OGC Candidate Standard for
Indoor Spatial Information
2013
).
In addition, new specialized standards are constantly developed; the continuous
adjustment of existing standards is ongoing. Currently, CityGML 2.0 is being
revised and discussed and a new version, 3.0, will be prepared. The major changes
include the revision of the LoD concept. Definitions of LoDs are currently vague,
informal and allow a great deal of ambiguity. Thus, the LoDs in the next version of
CityGML will be described by separately specifying:
•
semantic and geometric LoDs,
•
the definition of separate interior LoDs and LoDs for the building
s exterior shell
'
This division produces four different variants of LoD; each of these options
contains five levels of detail. This approach has so far been proposed only for the
Building semantic class, since it is complicated; however, it is possible to apply it to
other semantic classes. Different testing use-cases bring different requirements. The
division into indoor and outdoor LoD is important for combined indoor and outdoor
navigation. However, this new concept of LoD brings new challenges as well. It
will be composed of many combinations which it will be necessary to quantify and
sort (L¨wner et al.
2013a
). Benner et al. (
2013
) propose a solution to this task.
Another modification which can improve the use of indoor navigation is support
for dynamic (time-dependent) entities. Dynamic entities contain dynamic proper-
ties (e.g. energy demand) and moving objects (dynamic geometry). Dynamic
features and attributes are not yet supported in CityGML. The utilization of 3D
building models in navigation or in simulations has wider consequences including
