Programme

Mercredi 31 mai

14h Accueil

14h10 Session “Sensorielle”

14h10 : Nebula: An Affordable Open-Source and Autonomous Olfactory Display for VR Headsets (Charles JAVERLIAT – ECL/ENISE, LIRIS)

The impact of olfactory cues on user experience in virtual reality is increasingly studied. However, results are still heterogeneous and existing studies difficult to replicate, mainly due to a lack of standardized olfactory displays. In that context, we present Nebula, a low-cost, open-source, olfactory display capable of diffusing scents at different diffusion rates using a nebulization process. Nebula can be used with PC VR or autonomous head-mounted displays, making it easily transportable without the need for an external computer. The device was calibrated to diffuse at three diffusion rates: no diffusion, low and high. For each level, the quantity of delivered odor was precisely characterized using a repeated weighting method. The corresponding perceived olfactory intensities were evaluated by a psychophysical experiment on sixteen participants. Results demonstrated the device capability to successfully create three significantly different perceived odor intensities (Friedman test 𝑝 < 10−6, Wilcoxon tests 𝑝𝑎𝑑 𝑗 < 10−3), without noticeable smell persistence and with limited noise and discomfort. For reproducibility and to stimulate further research in the area, 3D printing files, electronic hardware schemes, and firmware/software source code are made publicly available.

14h40 : Influence of the visual quality of food on the ability to induce a desire to eat in virtual reality (Florian RAMOUSSE – ECL/ENISE, LIRIS)

Studies into food-related behaviors and emotions are increasingly being explored with Virtual Reality (VR). Applications of VR technologies for food science include eating disorder therapies, eating behavior studies and sensory analyzes. These applications involve 3D food stimuli intended to elicit cravings, stress, and/or emotions. However, the visual quality (i.e., the realism) of used food stimuli is heterogeneous, and this factor’s influence on the results has never been isolated and evaluated. In this context, this work aims to study how the visual quality of food stimuli, exposed in a virtual reality environment, influences the resulting desire to eat. 28 subjects without eating disorders were included in this protocol, who evaluated the desire to eat induced by 10 3D food stimuli, each duplicated in 7 quality levels (for a total of 70 stimuli). Results show that visual quality influences the desire to eat, and this effect depends on the type of food and users’ eating habits. We found two significant thresholds for visual quality: the first provides the minimal quality necessary to elicit a significant desire to eat, while the second provides the ceiling value above which increasing the quality does not improve further the desire to eat. These results allow us to provide useful recommendations for the design of experiments involving food stimuli

15h10 : Saisie de données par écriture manuelle pour les applications industrielles de la réalité virtuelle : influence de l’orientation du tableau et des retours sensoriels sur la performance (Nicolas FOURRIER – ECN, AAU)

La saisie de données textuelles en réalité virtuelle (RV) est une tâche critique dont l’importance ne cesse de grandir. C’est en particulier le cas pour les applications industrielles de la RV où les situations de saisie de données peuvent être courantes : communication entre collaborateurs, saisie de données techniques… Il existe aujourd’hui un gap de performance entre les outils classiques, comme les claviers physiques, et les méthodes de saisie virtuelles qui sont utilisées en RV. La saisie de données en RV se doit d’être efficace et facile à apprendre sans être frustrante. Nous présentons une méthode de saisie de texte basée sur la reconnaissance d’écriture manuelle qui répond à ces trois critères. Les utilisateurs peuvent saisir du texte en écrivant manuellement sur un tableau virtuel. Une étude utilisateur avec 40 participants a été menée pour étudier les meilleurs conditions d’écriture en terme d’orientation de tableau et de présence de retours sensoriels (visuel, haptique et audio). La vitesse d’écriture, le taux d’erreur, l’utilisabilité et la charge de travail sont étudiés. Cette étude montre que l’utilisation d’un tableau penché avec des retours sensoriels permet de maximiser les vitesses de saisie en minimisant la charge de travail. L’écriture manuelle en RV fait preuve d’une grande vitesse de saisie et utilisabilité après un court entrainement en comparaison avec d’autres méthodes de saisie virtuelles. Après 40 phrases d’entrainement, les participants atteignent en moyenne une vitesse de saisie de 14.5 mots par minute et un groupe d’utilisateurs expérimentés en RV atteint 16.16 mots par minute. La plus haute vitesse de saisie observée est de 21.11 mots par minute.

15h40 Pause

16h10 Session “Comportement”

16H10 : L’effet Proteus et la créativité avec l’incarnation de Leonardo da Vinci (Geoffrey GORISSE – ENSAM, LAMPA)

Virtual reality provides users with the ability to substitute their physical appearance by em- bodying virtual characters (avatars) using head-mounted displays and motion-capture tech- nologies. Previous research demonstrated that the sense of embodiment toward an avatar can impact user behavior and cognition. In this paper, we present an experiment designed to investigate whether embodying a well-known creative genius could enhance participants' creative performance. Following a preliminary online survey (N = 157) to select a famous character suited to the purpose of this study, we developed a VR application allowing parti- cipants to embody Leonardo da Vinci or a self-avatar. Self-avatars were approximately matched with participants in terms of skin tone and morphology. 40 participants took part in three tasks seamlessly integrated in a virtual workshop. The first task was based on a Guil- ford’s Alternate Uses test (GAU) to assess participants’ divergent abilities in terms of fluency and originality. The second task was based on a Remote Associates Test (RAT) to evaluate convergent abilities. Lastly, the third task consisted in designing potential alternative uses of an object displayed in the virtual environment using a 3D sketching tool. Participants em- bodying Leonardo da Vinci demonstrated significantly higher divergent thinking abilities, with a substantial difference in fluency between the groups. Conversely, participants embodying a self-avatar performed significantly better in the convergent thinking task. Taken together, these results promote the use of our virtual embodiment approach, especially in applications where divergent creativity plays an important role, such as design and innovation.

16h40 Influence of Scenarios and Player Traits on Flow in Virtual Reality (Élise LAVOUÉ – Université Jean Moulin Lyon 3, LIRIS)

Many studies have investigated how interpersonal differences between users influence their experience in Virtual Reality (VR) and it is now well recognized that user’s subjective experiences and responses to the same VR environment can vary widely. In this study, we focus on player traits, which correspond to users’ preferences for game mechanics, arguing that players react differently when experiencing VR scenarios. We developed three scenarios in a same VR environment that rely on different game mechanics and evaluate the influence of player traits on users’ perceived flow in each scenario. Our results show that 1) the type of scenario has an impact on specific dimensions of flow; 2) the scenarios have different effects on flow depending on the order they are performed, the flow preconditions being stronger when performed at last; 3) almost all dimensions of flow are influenced by the player traits, these influences depending on the scenario, 4) the Aesthetic trait has the most influences in the three scenarios. We finally discuss the findings and limitations of the present study that we believe has strong implications for the design of scenarios in VR experiences.

Jeudi 1er juin

9h30 Sessions “Doctorants ENSAM”

Présentations de 5 projets doctoraux de l’équipe Présence et Innovation du LAMPA et des Arts et Métiers. Les thématiques abordées sont les agents virtuels, d’incarnation d’avatars, d’apprentissage en RV et de santé.

10h20 Pause

10h45 Atelier Prospectif

12h Clôture