Mickael Naud

Haptic guides in cooperative virtual environments: Design and human performance evaluation

In this paper we simulate the use of two string based parallel robots in cooperative manipulation task. Two users standing in front of a large screen operate each robot. We propose two haptic guide models, and investigate their effects on cooperation, co-presence and users performance. In addition we also examine the effect of object-based force feedback in cooperative work. Ten volunteer subjects had to cooperatively perform a peg-in-hole task. Results revealed that haptic guides have a significant effect on task execution. They not only increase users performance but also enhance the sense of co-presence and awareness. Our investigations will help in the development of VR systems for cooperative assembly, surgical training and rehabilitation.

Modeling dynamic interaction in virtual environments and the evaluation of dynamic virtual fixtures

Virtual reality (VR) is a technology covering a large field of applications among which are sports and video games. In both gaming and sporting VR applications, interaction techniques involve specific gestures such as catching or striking. However, such dynamic gestures are not currently being recognized as elementary task primitives, and have therefore not been investigated as such. In this paper, we propose a framework for the analysis of interaction in dynamic virtual environments (DVEs). This framework is based on three dynamic interaction primitives (DIPs) that are common to many sporting activities: catching, throwing, and striking. For each of these primitives, an original modeling approach is proposed. Furthermore, we introduce and formalize the concept of dynamic virtual fixtures (DVFs). These fixtures aim to assist the user in tasks involving interaction with moving objects or with objects to be set in movement. Two experiments have been carried out to investigate the influence of different DVFs on human performance in the context of ball catching and archery. The results reveal a significant positive effect of the DVFs, and that DVFs could be either classified as performance-assisted or learning-assisted.

New Augmented Reality Techniques for Product Design: The Flip-Flop Menu

This paper presents two bimanual augmented reality (AR) interaction techniques for product design. The first technique allows the user to visualize 3D virtual object in his/her non-dominant hand while being able to map different textures on it using his/her dominant hand. The second technique is based on nine fiducial markers placed on a desk in front of the user. Two experiments were carried out using the second technique to compare four different markers arrangements and four viewing conditions. In these experiments, subjects were instructed to perform nine actions such as rotate the object, apply a texture on it, etc. Results of the first experiment revealed that a V-shape configuration was the best. Results of the second experiment revealed that camera placed behind the user was the more efficient condition.

Computer‐Assisted Generation of Patterns and Virtual Reality Techniques for Fashion Design

We present a methodology for the design of aesthetic patterns and their visualization on virtual clothes. Generated patterns are directly mapped on the dress of a virtual mannequin. Furthermore, patterns sets may be interactively mapped on the virtual dress using a specific 3D interaction technique called Back‐and‐Forth. Pattern generation involves different mathematical approaches such as iterated function systems (IFS) and nonlinear trajectory models. Both model parameters and color space exploration is performed through a simple user interface. This work contributes to promote both computer assistance in the context of mass customization for fashion design.