Section: Scientific Foundations
3D Human Computer Interface
Since more than 20 years, the fundamental concepts of the computer's desktop environments did not really evolve. Windows, Icons, Mouse, Pointer (WIMP) are always the 2D metaphors used by humans to interact with applications. The 2D window remains the medium of interaction for all 2D and 3D applications. Current windowing systems tend to use the 3D capabilities of modern computer's video cards, but only to add some specific visual effects, such as transparency or shadows.
In our daily activities, we use simultaneously more and more applications, and we display more and more windows on the same screen. In the meantime, there is a growing number of domains requiring applications to work on 3D objects while displaying and working with 2D information. However, the 2D windowing environments are not well adapted to the display and the interaction with such a great amount of information. Some studies did show that the use of a 3D space to organize information can ease the user's activity for the organization of 2D windows. In the case of the concurrent interaction with 3D objects and 2D information, the WIMP highlights its limits and addresses the need for the development of new interaction techniques and input devices. Consequently, the computer-human interfaces must evolve, and we think that the far future computer's desktop systems will be specific 3D environments, seamlessly incorporating collaborative features.
At a low level, virtual tools or action metaphors are needed in collaborative virtual environment to let the user focus on her/his activity rather than on the manipulation of the physical devices  . This should be done by matching the interaction technique with the physical properties of the input device. Useless interactions should be removed or replaced with high level virtual tools. Those tools are used to transpose the user intentions, and in a collaborative framework, each public action is to be represented in the remote user's environments, to let them understand the ongoing global activity.
At a higher level, the concept of "3D application" must be defined. A 3D desktop should be able to allow the user to interact simultaneously with several 3D applications, such as 2D windowing systems let users interact with several 2D applications at the same time. A 3D application is roughly a set of 3D objects and 3D tools. Handling several 3D applications thus means that the 3D desktop has to manage several sets of objects and tools, which are not necessarily spatially related. The 3D desktop must also provide specific tools to handle those 3D applications.
We are working on the software and the ergonomic parts needed to create such an environment.