Laure Leroy

Université de Vincennes - Paris 8 | UP8 · Département Hypermédias

Virtual Reality Head-Mounted Displays (HMDs) reached the consumer market and are used for learning purposes. Risks regarding visual fatigue and high cognitive load arise while using HMDs. These risks could impact learning efficiency. Visual fatigue and cognitive load can be measured with eye tracking, a technique that is progressively implemented i...

In monocular see-through augmented reality systems, each eye is stimulated differently by a monocular image that is superimposed on the binocular background. This can impair binocular fusion, due to interocular conflict. As a function of visual characteristics, the latter can have a greater or lesser impact on user comfort and performance. This stu...

Purpose Do apparatuses and eyestrain have effects on learning performances and quality of experience? Materials and Methods: 42 participants played a serious game simulating a job interview with a Samsung Gear VR Head-Mounted Display (HMD) or a computer screen. Participants were randomly assigned to 3 groups: PC, HMD biocular, and HMD stereoscopy (...

Monocular augmented reality devices are used in aviation to help civilian or military pilots in their flying task. Given that the image is presented in front of only one eye, the two eyes are not stimulated in the same way and it can create a phenomenon known as binocular rivalry. It appears when the brain is not able to merge the two visuals infor...

Purpose: It is hypothesized that cyclical stereoscopy (displaying stereoscopy or 2D cyclically) has effect over visual fatigue, learning curves and quality of experience, and that those effects are different from regular stereoscopy. Materials and Methods: 59 participants played a serious game simulating a job interview with a Samsung Gear VR Head...

Les casques de réalité virtuelle sont de plus en plus intégrés dans l'enseignement et la formation Parallèlement, l'utilisation des serious games (SG) est de plus en plus répandue. Notre expérience consiste à interroger le couplage des SG avec la Réalité Virtuelle (RV) en visiocasque (HMD).Plus de données sur les HMD accessibles au grand public son...

A monocular augmented reality device allows the user to see information that is superimposed on the environment. As it does not stimulate both eyes in the same way, it creates a phenomenon known as binocular rivalry. The question therefore arises as to whether monocular information should be displayed to a particular eye and if an ocular dominance...

Purpose: This study explores eyestrain and its possible impacts on learning performances and quality of experience using different apparatuses and imaging. Materials and Methods: 69 participants played a serious game simulating a job interview with a Samsung Gear VR Head Mounted Display (HMD) or a computer screen. The study was conducted according...

Les casques de réalité virtuelle, après 50 ans de développement, semblent en passe d’être adoptés par le grand public. En parallèle, et parfois au croisement, les Serious Games sont de plus en plus choisis comme médiation des connaissances. Ainsi, l’utilisation de dispositifs combinant les Serious Games et la Réalité Virtuelle à des fins d’apprenti...

À travers l'analyse des premières photographies stéréoscopiques du xixe siècle, des films en 3Ds en passant par les applications en réalité virtuelle, cet ouvrage réunit les contributions d’artistes, de stéréographes, de cinéastes et de chercheurs qui dressent un état des lieux sur les connaissances scientifiques et les expérimentations artistiques...

Despite the advantages of gestural interactions, they involve several drawbacks. One major drawback is their negative physical impacts. To reduce them, it is important to go through a process of assessing risk factors to determine the interactions’ level of acceptability and comfort so as to make them more ergonomic and less tiring. We propose a me...

Ease of accommodation is the speed at which the curve of human crystalline lens changes in moving from a nearby object to a distant object or vice versa. The more tired the visual system, the more time it will take to accommodate to a point. Stereoscopic acuity is the accuracy with which a human can perceive the difference in depth between two obje...

Suppressing high spatial frequencies relaxes the accommodation. If this relaxation of accommodation is directed to the areas of highest disparity, that is areas of the most marked conflict between vergence and accommodation, one can succeed in reducing this conflict by imposing a less strict accommodation, which will then more easily follow the sti...

This chapter discusses the function of the eye, depth perception without stereoscopy, depth perception through stereoscopic vision, perception of inclinations and curves and artificial stereoscopic vision. Light and shadows completely change depth perception. When an object partially hides another, the brain interprets the hidden part of the object...

Nowadays, actual stereoscopic 3D renderers use two cameras to render images to the screen. These two cameras have parallel optical axis. It is well know that if cameras converge, then it produces distortions called vertical parallaxes. These distortions are supposed to stress visual system, but we do not know the effect on perception. In this artic...

In a context in which virtual reality making use of S3D is ubiquitous in certain industries, as well as the substantial amount of literature about the visual fatigue S3D causes, we wondered whether the presentation of intermittent S3D stimuli would lead to improved depth perception (over monoscopic) while reducing subjects' visual asthenopia. In a...

For some years, a lot of Stereoscopic 3D contents have been released. Even if the depth sensation is realistic, it is still not perfect and uncomfortable. The objective of our work is to use the gaze of the user to bring closer artificial vision and natural vision to increase the precision of the perception and decrease visual fatigue. For example,...

In order to make children develop good safety habits on the streets, it is very important to educate them on this subject at an early age. The technological advancements allow the creation of applications for training assistance and support. Virtual Reality and Augmented Reality are some of the best suitable scientific domains for successful traini...

Malgré les avantages des interactions gestuelles, elles impliquent parfois quelques inconvénients. Un des inconvénients principaux est lié à leurs impacts physiques négatifs. Afin de réduire ceux-ci, il est important de passer par un processus d'évaluation des facteurs de risques qui permet de déterminer leur niveau d'acceptabilité et de confort. C...

A dichotomy exists in the way virtual embodiments are currently studied: embodied entities are considered by conversational approaches as other selves whereas avatar approaches study them as users' hosts. Virtual reality applications such as in our case study often propose a different, in between embodiment experience. In the context of a virtual h...

Heritage valorisation is one of the greatest challenges that face countries in preserving their own identity from the globalization process. One of those scientific areas which allow this valorisation to be more attractive and at its bravest is the augmented reality. In this paper, we present an innovative augmented reality telescope used by touris...

Virtual Reality has recognized assets to address some cognitive rehabilitation issues. The purpose of this poster is to present an overview of the design of AGATHE, a tool for personalized rehabilitation of cognitive functions based on simulated Basic and Instrumental Activities of Daily Living (sBADL and sIADL).

Every year, tens of thousands of people fall victim to one of invalidating neurological pathologies. Acquired brain injury leads to cognitive impairment and heavy loss of autonomy. Rehabilitation interventions are needed to enable people to recover capacity and return to Instrumental Activities of Daily Living (iADL), such as grocery shopping. Unfo...

In this paper, we introduce a method for using jointly the resources of the virtual reality and CAD. The aim is to improve the designers' productivity, particularly in the automotive field. This paper presents a first approach using a bidirectional link between CAD and virtual reality systems that allows parts product modification during a function...

As stereoscopic devices become widely used (immersion-based working environments, stereoscopically viewed movies, autostereoscopic screens, etc), exposure to stereoscopic images can become lengthy, and some eyestrain can set in. We propose a method for reducing eyestrain induced by stereoscopic vision. After reviewing sources of eyestrain linked to...

Stereoscopic devices are widely used (immersion-based working environments, stereoscopically-viewed movies, auto-stereoscopic screens). In some instances, exposure to stereoscopic immersion techniques can be lengthy, and so eye strain sets in. We propose a method for reducing eye strain induced by stereoscopic vision. After reviewing sources of eye...

Stereoscopic devices become widely used (immersion-based working environments, stereoscopically viewed movies, auto-stereoscopic screens...). In some instances, exposure to stereoscopic immersion techniques can be lengthy, and eyestrain sets in. We propose a method for reducing eyestrain induced by stereoscopic vision. After reviewing sources of ey...

Through Virtual Reality techniques, it is possible to create virtual objects entirely designed using computer programs. The greatest claimed advantage is that designers can modify virtual objects as much as they wish. When an object suits them, they can then decide to build a real object, using the virtual object as a template. But two important qu...

Stereoscopic displays are increasingly used for computer-aided design. The aim is to make virtual prototypes to avoid building real ones, so that time, money and raw materials are saved. But do we really know whether virtual displays render the objects in a realistic way to potential users? In this study, we have performed several experiments in wh...

Les dispositifs d'immersion stéréoscopique sont très répandus et tendent à l'être de plus en plus (travail en immersion, film projeté en vision stéréoscopique, écrans auto-stéréoscopiques...). Dans certains cas, les immersions peuvent être longues et la fatigue visuelle s'installe. Nous donnons une méthode pour diminuer la fatigue visuelle liée à l...

Virtual environments are increasingly used to replace real prototypes, but are we sure that shape perception is the same in both environments, i.e. can we affirm that the shapes that are designed and validated in virtual environ-ments will be perceived the same once a physical proto-type has been built? This study traces a series of per-ception tes...

A grasp exoskeleton actuated by a string-based platform is proposed to provide the force feedback for a user's hand in human-scale virtual environments. The user of this interface accedes to seven active degrees of freedom in interaction with virtual objects, which comprises three degrees of translation, three degrees of rotation, and one degree of...

String-based interfaces are promising to provide the force feedback for the operator of a virtual environment. However their performance is affected by some problems like instability, inertia and response lag, especially in the large environments. A hybrid position/force control method is presented in this paper. This approach is experimented on an...