Cédric Fleury

An asymmetric 2D Pointer/3D Ray for 3D interaction within collaborative virtual environments

In this paper we present a new metaphor for interaction within Collaborative Virtual Environments (CVE). This metaphor is dedicated to non-immersive or semi-immersive 3D interactions, for which users cannot afford to buy expensive devices neither for 3D visualization of their virtual environment nor for interaction. With these low-cost restrictions, we think that it is more effective to use basic 2D metaphors rather than to try to adapt 3D virtual metaphors which would be more difficult to use because of the poor immersion level offered by such systems. The problem that will arise within a CVE is that it is difficult to make a user aware of the 2D metaphors used by another user, because they are not associated with a 3D virtual object of the shared universe. So our idea is to provide to a user a 3D virtual ray (using ray-casting for object selection) that would act like a 2D pointer on the screen, allowing the user to only control the 2D position of the closest ray end, and calculating the orientation of the ray so that its projection on the screen would always be a point. This way, since the user is controlling a 3D virtual ray, the other users can be made aware of his activity. To test the efficiency of this 2D Pointer / 3D Ray, we have made some experiments making users compare different devices to realize some simple selection and manipulation tasks. The results show that this kind of 2D solution is efficient and allows 3D interaction within Virtual Environments by people who cannot afford expensive immersive hardware. This new metaphor allows more users to collaborate within CVE.

Evaluation of remote collaborative manipulation for scientific data analysis

In the context of scientific data analysis, we propose to compare a remote collaborative manipulation technique with a single user manipulation technique. The manipulation task consists in positioning a clipping plane in order to perform cross-sections of scientific data that show several points of interest located inside these data. For the remote collaborative manipulation, we have chosen to use the 3-hand manipulation technique proposed by Aguerreche et al., which is very suitable with a remote manipulation of a plane. We ran two experiments to compare the two manipulation techniques with some participants located in two different countries. These experiments has shown that the remote collaborative manipulation technique was significantly more efficient than the single user manipulation when the 3 points of interest were far apart inside the scientific data and, consequently, when the manipulation task was more difficult and required more precision. When the 3 points of interest were close together, there was not significant difference between the two manipulation techniques.

Collaborative exploration of 3D scientific data

This demonstration introduces new ways for exploring Collaborative Virtual Environments (CVE) that contain 3D scientific data sets obtained by simulation. In order to make decisions accordingly to their collective knowledge and understanding of the simulation, the users must collaborate and share experiences and comments. We provide tools to enable a good coordination between the users, and to make each user aware of the activity of others. Each user can navigate within the CVE: change her own position, orientation and scale. Each user can also add annotations within the virtual universe. We propose several 3D layouts for the presentation of the data, associated with different 3D navigation tools. Consequently, the user can explore the data accoording to various parameters such as time or temperature. Last we propose a new 3D interaction tool, called 2D Cursor / 3D Pointer, dedicated to selection and manipulation of 3D objects, and application control. This 2D cursor is associated with a 3D geometry in order to make people aware of the activity of the users who are using this tool.

Collaborative exploration in a multi-scale shared virtual environment

For the 3DUI 2012 contest, we propose a set of metaphors that enable two users to collaborate to find hidden targets in a 3D virtual environment. They are not allowed to communicate by talking or chatting, but only by interacting with shared virtual objects. We propose three solutions to enable one of the users to help the other one to navigate toward targets: displaying direction arrows, lighting up the path to one target, and remotely moving the second user.