Exploring Virtual Worlds

Today, every virtual world relies on its own technology and therefore requires a particular “customer.” We can’t walk around Second Life from World of Warcraft, for example. It’s all right as long as there are two or three of these universes. What do we do when there are dozens of them, as is already the case? Can we ever hope for a standard that allows internet users to navigate between virtual worlds using a single browser, or even using the same avatar?

A standard for navigating between different virtual worlds using a single browser has been in existence for more than twenty years: VRML (Virtual Reality Modeling Language), a “web 3D” technology that has never really taken off.


There were many reasons for this lack of success. For example, it was said that the problem with VRML was that it was not multi-user; but there were a multitude of multi-user servers for VRML, some open source, like Deep Matrix, another commercial, like Blaxxun or Community Place, from Sony. This misunderstanding was because the multi-user aspect was not defined directly by the standard, but left to the choice of the server designers.

The file format was said to be too heavy, but often it was because the existing 3D modelers were unable to produce a compressed file (for example, they generated hundreds of points forming a sphere in the output file, when they would have only had to write the English word Sphere). The VRML was not a format but a language, and, like all languages, only a human being can use it optimally and cleverly. Automatic generation of code doesn’t do any good. This peculiarity of the VRML was, without doubt, a handicap for professionals, equipped with powerful 3D modelers that proved to be poorly adapted to this technology.

On the other hand, for the broke amateur, it was the dream: it was possible to create a relatively sophisticated VRML world that would fit on a few tens of kilobytes and without using expensive software. The idea of programming a graphics scene may seem bizarre today. It should be noted that at the time, the practice was quite widespread. There were several open source computer-generated imaging software, Persistence of Vision being the best known, based on this concept of visual programming.

However, today, while VRML still exists, it is still not imposed. This is all the more unfortunate because, made compatible with XML, via the X3D standard, it now has new advantages. This means, first of all, that it is likely to be generated via another XML file. This also means that it is possible, for example, to take a drawing made in vector graphics (SVG) and transform it into a 3D scene, or to take a semantic database in RDF and visualize it directly in the form of a virtual world.

Around the VRML/X3D standard, various “sub-standards” such as H-Anim are developed. It defines a set of specifications to represent the human form, and thus most avatars. H-Anim helps to avoid various interoperability problems, for example, an animation program that would like to move the elbow of an avatar to discover that he does not have one, or so that, when meeting two avatars from different worlds, one does not measure four meters high and the other eighteen centimeters! One can thus dream of an encounter between virtual universes. On Croquet, some are working on it, but progress is slow. Despite the considerable work done by the x3d enthusiasts, it seems that all this progress is taking place in the general indifference of the designers of most of the existing virtual universes.

Towards a “Universal Player of Virtual Worlds”?

In the meantime, it is not impossible that some interoperability will be achieved through tinkering. For example, there is a bridge between Croquet and Second Life. After placing an object in both worlds, it becomes possible, via a script, to control both objects from any of the two systems.

The search for a standard, paving the way for the creation of a “universal player of virtual worlds” which would fulfill for these the same role as Internet Explorer or Firefox with Web pages, is not abandoned. The adoption of a future standard is left to the market rather than to an agreement between the parties. In this search for the Universal reader, Linden Lab tried to take advantage by making its client open source. The Multiverse society, on the other hand, has developed a new policy. Not open source, it has nevertheless imagined a particularly original business model: the company offers anyone who wants to download its tools for creating worlds and asks for money only from those who already make it thanks to their technology. As with Linden Lab, the idea is to impose a “private VRML”: different worlds are accessible from the one and only customer. Whether at Linden Lab or Multiverse, the goal is the same: to ensure that its technology will spread widely at the expense of others to achieve a state of Monopoly and establish a de facto standard. In the meantime, this will still be the user to wipe the plasters.