We are working to create a virtual London which will have realistic urban form linked to GIS to provide a rich, spatially referenced information content. This can be achieved by enabling the 3D built form of the virtual city in multi-user environments whereby any number of users can be present in the same model. Each user within the virtual city model is represented by an avatar. An avatar is the user's representation of their bodily presence in the virtual city. Although avatars represent the user they need not necessarily look like them or even have human form for that matter.
Avatars are under user control, they move as the user navigates around the virtual city.
When multiple users are in the virtual city, via their avatars, they can meet and talk to one another. Through the ability to meet and talk to other people in the virtual city, it is hoped the a measure of life and spontaneity found in real cities will develop. A screen-shot from one of CASA's virtual city prototypes called 'Wired Whitehall' is shown in figure 4. We also believe that to be a true virtual city its built form needs to be geographically referenced, with all its elements appropriately represented in some form of object-orientated spatial database. The virtual city in essence becomes an information system in which multiple users could enter and walk through and query.