Section: New Results

Collaborative Virtual Environments

Collaborative virtual environments for training

Collaborative Virtual Training with Physical and Communicative Autonomous Agents Thomas Lopez, Valérie Gouranton, Florian Nouviale, Rozenn Bouville-Berthelot, Bruno Arnaldi

Virtual agents are a real asset in collaborative virtual environment for training (CVET) as they can replace missing team members. Collaboration between such agents and users, however, is generally limited. We presented a whole integrated model of CVET focusing on the abstraction of the real or virtual nature of the actor to define a homogenous collaboration model. First, we defined a new collaborative model of interaction. This model notably allows to abstract the real or virtual nature of a teammate. Moreover, we proposed a new role exchange approach so that actors can swap their roles during training. The model also permits the use of physically based objects and characters animation to increase the realism of the world. Second, we design a new communicative agent model, which aims at improving collaboration with other actors using dialog to coordinate their actions and to share their knowledge. Finally, we evaluated the proposed model to estimate the resulting benefits for the users and we show that this is integrated in existing CVET applications [20] .

Exchange of avatars : Toward a better perception and understanding Thomas Lopez, Rozenn Bouville-Berthelot, Florian Nouviale, Valérie Gouranton, Bruno Arnaldi

The exchange of avatars, i.e. the actual fact of changing once avatar with another one, is a promising trend in multi-actor virtual environments. It provides new opportunities for users, such as controlling a different avatar for a specific action, retrieving knowledge belonging to a particular avatar, solving conflicts and deadlocks situations or even helping another user. Virtual Environments for Training are especially affected by this trend as a specific role derived from a scenario is usually assigned to a unique avatar. Despite the increasing use of avatar exchange, users' perception and understanding of this mechanism have not been studied. We propose two complementary user-centered evaluations that aim at comparing several representations for the exchange of avatars; these are termed exchange metaphors. Our first experiment focuses on the perception of an exchange by a user who is not involved in the exchange, and the second experiment analyzes the perception of an exchange triggered by the user. Results show that the use of visual feedback globally aids better understanding of the exchange mechanism in both cases. Our first experiment suggests, however, that visual feedback is less efficient than a simple popup notification in terms of task duration. In addition, the second experiment shows that much simpler metaphors with no visual effect are generally preferred because of their efficiency [19] .

An interaction abstraction model for seamless avatar exchange in CVET Rozenn Bouville-Berthelot, Thomas Lopez, Florian Nouviale, Valérie Gouranton, Bruno Arnaldi

Collaboration and interaction between users and virtual humans in virtual environments is a crucial challenge, notably for Collaborative Virtual Environments for Training (CVET). A training procedure, indeed, often involves several actors: trainees, teammates and many times a trainer. Yet, a major benefit of CVET is to propose to users to be trained even if the required number of person needed by the procedure is not available. Therefore, almost every CVET use autonomous virtual humans to replace the missing person. We have proposed to improve the effective collaboration between users and virtual humans involved in a complex task within CVET. Using an entity called the "Shell", we are able to wrap the features common to both users and virtual humans. It gives us an abstraction level to pool the management of the main processes useful to control an avatar, interact with the environment and gather knowledge from a CVET. Besides, the Shell allows seamless exchange of avatars during a procedure. Thanks to the Shell, the exchange can be carried out at any time during a task while preserving all the data associated to a role in a procedure [29] .

#SEVEN: a Sensor Effector Based Scenarios Model for Driving Collaborative Virtual Environment Guillaume Claude, Valérie Gouranton, Rozenn Bouville-Berthelot, Bruno Arnaldi

We introduced #SEVEN, a sensor effector model that enables the execution of complex scenarios for driving Virtual Reality applications. #SEVEN is based on an enhanced Petri net model which is able to describe and solve intricate event sequences. Our model also proposes several useful features for the design of collaborative scenarios for Collaborative Virtual Environments such as versatile roles and Activity Continuum. We also illustrate its usage it by describing a demonstrator that presents an implementation of our model [30] .

Collaborative virtual environments for ergonomics: embedding the design engineer role in the loop Thierry Duval, collaboration with Charles Pontonnier and Georges Dumont (MIMETIC).

We have proposed to define the role and duties of a design engineer involved in a collaborative ergonomic design session supported by a 3D collaborative virtual environment. For example, such a session can be used to adapt the manual task an operator must achieve in the context of an industrial assembly line. We first presented the interest of such collaborative sessions. Then we presented a related work explaining the need of proper 3DCVE and metaphors to obtain efficient collaborative ergonomic design sessions. Then we proposed a use case highlighting the type of metaphor such engineers need to have to be efficient in such a framework [40] .

Collaborative virtual environments and awareness

Improving Awareness for 3D Virtual Collaboration by Embedding the Features of Users' Physical Environments and by Augmenting Interaction Tools with Cognitive Feedback Cues Thierry Duval, Thi Thuong Huyen Nguyen, Valérie Gouranton, collaboration with MimeTic

The feeling of presence is essential for efficient interaction within Virtual Environments (VEs). When a user is fully immersed within a VE through a large immersive display system, his/her feeling of presence can be altered because of disturbing interactions with his/her physical environment, such as collision with hardware parts of the system or loss of tracking. This alteration can be avoided by taking into account the physical features of the user as well as those of the system hardware and embedding them in the VE. Moreover, the 3D abstract representation of these physical features can also be useful for collaboration between distant users because they can make a user aware of the physical limitations of the others he/she is collaborating with. We used the Immersive Interactive Virtual Cabin (IIVC) model to obtain this virtual representation of the user's physical environment and we illustrated how this representation can be used in a collaborative navigation task in a VE. We also presented how we can add 3D representations of 2D interaction tools in order to cope with asymmetrical collaborative configurations, providing 3D cues for a user to understand the actions of the others even if he/she is not fully immersed in the shared VE [15] .

From 3D Bimanual Toward Distant Collaborative Interaction Techniques: An Awareness Issue Morgan Le Chénechal, Thierry Duval, Valérie Gouranton, Bruno Arnaldi, collaboration with b<>com

CVE involve the use of complex interaction techniques based on specific collaborative metaphors. The design of these metaphors may be a difficult task because it has to deal with collaborative issues that came from sparse research areas (Human-Computer Interfaces, Human-Human Interactions, Networking, Physiology and Social Psychology). Metaphors for bimanual interactions have been developed for a while essentially because it is a widely spread area of interest for common tasks. Bimanual interactions involve the simultaneous use of both hands of the user in order to achieve a goal with better performances compared to uni-manual interactions thanks to a natural skill that is proprioception. This collaborative aspect could certainly be a helpful entry point in the design of efficient collaborative interaction techniques extended from improved bimanual metaphors. However, the proprioceptive sense cannot be considered in the same way, and additional features must be proposed to be able to collaborate efficiently. Thus, awareness is a key to let CVE be usable and the availability of collaborative feedbacks is essential to extend bimanual interactions toward collaborative ones. In this paper, we based our study on existing work on bimanual and collaborative interaction techniques trying to draw similarities between them. We emphasize common points between both fields that could be useful to better design both metaphors and awareness in CVE [34] .

A survey of communication and awareness in collaborative virtual environments Thi Thuong Huyen Nguyen, Thierry Duval

In the domain of Collaborative Virtual Environments (CVEs), many virtual worlds, frameworks and techniques are built based on a specific and direct purpose. There is not a general and still good and efficient enough solution for all the collaborative systems. Depending on the purpose of the collaborative work, the techniques of interaction and of manipulation change from one application to another. Despite this difference between interaction techniques, they always benefit greatly from awareness features that help in explicating implicit knowledge related to one's own and others' working activities as well as to virtual workspace. In addition, people in CVEs also use communication channels to negotiate shared understandings of task goals, of task decomposition and of task progress. Therefore, awareness and communication are usually considered as “instruments" to complete collaborative tasks in the environment. However, few research work have been devoted to improving the awareness and the communication channels in CVEs for a better collaboration between users. We have studied the importance of awareness and communication in collaborative virtual environments. We have investigated different kinds of awareness which need to be carefully designed. We have discussed different communication means and how to cope with this diversity, so we can benefit from the availability of different peripheral devices and can find an effective communication means to work together. Finally, we have made some propositions to overcome these actual limitations of CVEs [37] .

Collaborative virtual environments and software engineering

When model driven engineering meets virtual reality: feedback from application to the Collaviz framework Thierry Duval, collaboration with Arnaud Blouin and Jean-Marc Jézéquel (DIVERSE).

Despite the increasing use of 3D Collaborative Virtual Environments (3D CVE), their development is still a cumbersome task. The various concerns to consider (distributed system, 3D graphics, etc.) complexify the development as well as the evolution of CVEs. Software engineering recently proposed methods and tools to ease the development process of complex software systems. Among them, Model-Driven Engineering (MDE) considers models as first-class entities. A model is an abstraction of a specific aspect of the system under study for a specific purpose. MDE thus breaks down a complex system into as many models for different purposes, such as: generating code from models; building domain specific programming/modeling languages (DSL); generating tools such as graphical or textual editors. We have leveraged MDE for developing 3D CVEs. We showed how the Collaviz framework took benefits from a DSL we built. The benefits are multiple: 3D CVE designers can focus on the behavior of their virtual objects without bothering with distributed and graphics features; configuring the content of 3D CVEs and their deployment on various software and hardware platforms can be automated through code generation. We detailed the development process we propose and the experiments we conducted on Collaviz [31] .