The development of mobile platform’s technology induces innovative services and applications.The increasing bandwidth of these mobile platforms’ communication system allows the transmission of larger amounts of information.

On the other hand, the increased accuracy and integration of GPS equipment in mobile platforms is suitable for providing services and applications context-aware of the user’s location, like navigation and orientation services.

This project’s main goal is the development of procedures for creating large three-dimensional models of urban virtual environments that can be used in services and applications to provide the user an hypermedia interactive virtual environment of the area surrounding it’s location.

This kind of services and applications can be widely adopted in solutions from virtual tourism to facilities maintenance or urban planning, among a large variety.

The issue of interoperability in Geographic Information Systems, suggests the need to develop procedures towards structuring and integrating georeferenced information from multiple sources, in accordance with the emerging standards for geomatics and geographical information, namely ISO 19100 series (TC 211) and OpenGIS (OGC).

These procedures will lead to a structured model that must take into account the highly complex nature of urban environments, as well as a great number of information providers, geographic redundancy caused by diversity of themes on the same geographic data and temporal divergences on data gathering.

Modelling large virtual environments requires normally great human intervention. On the other hand there exists a large amount of information about the real environments to be modelled, from different data sources like GIS, relational databases, documents and images. All this information has a great potential for the 3D modelling of these virtual environments by automatic procedures.

One of the key features of such a system, is enabling rapid prototyping of large virtual environments, that can be progressively refined, in order to achieve a greater level of realism.

These virtual environments will enable different kind of users to interact with different classes of information in diverse visual presentations, based on its profile.

As mobile platforms have limited processing power and limited bandwidth, it’s essential to develop procedures for quick extraction of virtual environment’s scenes with different levels of detail, from the user’s location and context.