Papers in PDF format

PITS (Populated Information Terrains), allowing to share the data with other users and be aware of their actions. Q-Pit follows the first of the four
approaches just mentioned and uses an attribute mapping script to define how the intrinsic and extrinsic dimensions are used. VR-Vibe uses the statistical
method and offers special "points of interest" when the user makes a query. Finally, VR-Mapper implements the third approach, generating a hyperstructure
reminiscent of a cone-tree.
VizNet
Developed at the Institute of System Science in Singapore, VizNet [Fair93] is a multimedia visualization system for different types of data, from single
complex objects to large collections of objects. The user can choose appropriate visualization models depending on different degrees of interest, for instance
a sphere representation shows the inspected information in the center of the sphere and related information radially around it. Size, color and other visual
attributes are used to encode particular proprieties of the inspected data.
Hyperbolic Visualization
This system [Munz95], a variant of the cone-tree, takes advantage of non-Euclidean hyperbolic geometry to allow the display of both large structures and
detail at the same time.
3 Legibility and cyberspace
Studies in urban planning show that a city can be easier to live in when some characteristic structures are present. Kevin Lynch found more than thirty years
ago that there are five important features contributing to the legibility of a city: districts, landmarks, paths, nodes and edges. The legibility of an urban
environment, or generally a space, means the ease with which one can build a cognitive map of it in order to navigate through it. Researchers at the
University of Nottingham used this in a prototype system called LEADS, which improves the legibility of abstract data spaces [Ingr95]. As the authors point
out, the World Wide Web is a typical abstract data space and its legibility definitely affects the navigation. Describing the dimensionality of cyberspace,
Benedikt [Bene91] introduces the concept of extrinsic and intrinsic dimensions. The first are the classic x,y,z spatial dimensions, the second are attributes
like shape, size, color or spin which are logically independent of the spatial position. By carefully choosing the extrinsic attributes, the amount of
information in an abstract data space can be increased without relying on text annotations or external legends, which could reduce the legibility (although
legibility is related with text in the common sense).
4 Translating bookmarks into VRML
Netscape
One of the most popular web browsers, Netscape Navigator, automatically generates a bookmarks file. When a user exploring the net wants to take note of a
particular URL[*] , the Netscape browser allows to add this address in the bookmarks list for future reference. This way, anybody can create a personal
selection of the web. The bookmarks can later be selected from a pull-down menu, but this quickly becomes unpractical as the list grows. One way to solve
this problem is to define submenus; even so, other information included in the bookmarks file are harder to access. A 3D representation of this file could
empower the user with more information and easier navigation.
VRML
VRML (Virtual Reality Modeling Language) [3] is a standard created in 1994 for a platform-independent exchange of 3D worlds over the net. Based on
Silicon Graphics' Inventor, VRML can be used to define a tree structure where every node is a geometric primitive, an attribute (like material or texture), a
light source or a geometric transformation. Moreover, a geometric primitive can be associated with a URL, enabling users to make links to other 3D worlds
but also anything else on the web, like HTML sites.
3D Bookmarks Generator
Our generator, BED (Bookmarks Exploring Dabbler), reads a netscape bookmarks file, parses it and generates a VRML file. A VRML browser can be used
to visualize the scene and navigate through it. The choice of generating a VRML script allows to work over the network in a platform-independent way, but
also limits the kind of possible interaction to that allowed by VRML browsers (see section 7).
5 Data representation and navigation hints
Using Benedikt's terminology, the bookmarks file information is mapped onto the intrinsic and extrinsic dimensions of our cyberspace. We will refer to a
bookmarks file entry as "link".
Extrinsic dimensions
A link's position in space depends on its position in the bookmarks menu structure. Groups of links are always situated inside big globes, which have a
similar role as submenus or districts as explained in [Ingr95]. For example, if the bookmarks are organized in six submenus, there will be six globes and
each of them will contain the corresponding links. Also, because the maximal size of a globes is fixed, a menu can be represented with more than one globe
if it has many entries. All globes are situated in circular configuration, like files in a cone-tree level. At the moment, the position of a link inside a globe is
not significative.