Maud Marchal

Bio: Maud Marchal is an academic researcher from University of Rennes. The author has contributed to research in topics: Haptic technology & Virtual reality. The author has an hindex of 26, co-authored 128 publications receiving 1923 citations. Previous affiliations of Maud Marchal include University of British Columbia & Institut Universitaire de France.

Shake-your-head: revisiting walking-in-place for desktop virtual reality

Abstract: The Walking-In-Place interaction technique was introduced to navigate infinitely in 3D virtual worlds by walking in place in the real world. The technique has been initially developed for users standing in immersive setups and was built upon sophisticated visual displays and tracking equipments.In this paper, we propose to revisit the whole pipeline of the Walking-In-Place technique to match a larger set of configurations and apply it notably to the context of desktop Virtual Reality. With our novel "Shake-Your-Head" technique, the user is left with the possibility to sit down, and to use small screens and standard input devices such as a basic webcam for tracking. The locomotion simulation can compute various motions such as turning, jumping and crawling, using as sole input the head movements of the user. We also introduce the use of additional visual feedback based on camera motions to enhance the walking sensations.An experiment was conducted to compare our technique with classical input devices used for navigating in desktop VR. Interestingly, the results showed that our technique could even allow faster navigations when sitting, after a short learning. Our technique was also perceived as more fun and increasing presence, and was generally more appreciated for VR navigation.

The magic barrier tape: a novel metaphor for infinite navigation in virtual worlds with a restricted walking workspace

Abstract: In most virtual reality simulations the virtual world is larger than the real walking workspace. The workspace is often bounded by the tracking area or the display devices. This paper describes a novel interaction metaphor called the Magic Barrier Tape, which allows a user to navigate in a potentially infinite virtual scene while confined to a restricted walking workspace. The technique relies on the barrier tape metaphor and its "do not cross" implicit message by surrounding the walking workspace with a virtual barrier tape in the scene. Therefore, the technique informs the user about the boundaries of his walking workspace, providing an environment safe from collisions and tracking problems. It uses a hybrid position/rate control mechanism to enable real walking inside the workspace and rate control navigation to move beyond the boundaries by "pushing" on the virtual barrier tape. It provides an easy, intuitive and safe way of navigating in a virtual scene, without break of immersion. Two experiments were conducted in order to evaluate the Magic Barrier Tape by comparing it to two state-of-the-art navigation techniques. Results showed that the Magic Barrier Tape was faster and more appreciated than the compared techniques, while being more natural and less tiring. Considering it can be used in many different virtual reality systems, it is an interaction metaphor suitable for many different applications, from the entertainment field to training simulations scenarios.

Elastic-Arm: Human-scale passive haptic feedback for augmenting interaction and perception in virtual environments

Abstract: Haptic feedback is known to improve 3D interaction in virtual environments but current haptic interfaces remain complex and tailored to desktop interaction. In this paper, we introduce the “Elastic-Arm”, a novel approach for incorporating haptic feedback in immersive virtual environments in a simple and cost-effective way. The Elastic-Arm is based on a body-mounted elastic armature that links the user's hand to her shoulder. As a result, a progressive resistance force is perceived when extending the arm. This haptic feedback can be incorporated with various 3D interaction techniques and we illustrate the possibilities offered by our system through several use cases based on well-known examples such as the Bubble technique, Redirected Touching and pseudo-haptics. These illustrative use cases provide users with haptic feedback during selection and navigation tasks but they also enhance their perception of the virtual environment. Taken together, these examples suggest that the Elastic-Arm can be transposed in numerous applications and with various 3D interaction metaphors in which a mobile hap-tic feedback can be beneficial. It could also pave the way for the design of new interaction techniques based on “human-scale” egocentric haptic feedback.

Joyman: A human-scale joystick for navigating in virtual worlds

Abstract: In this paper, we propose a novel interface called Joyman, designed for immersive locomotion in virtual environments. Whereas many previous interfaces preserve or stimulate the users proprioception, the Joyman aims at preserving equilibrioception in order to improve the feeling of immersion during virtual locomotion tasks. The proposed interface is based on the metaphor of a human-scale joystick. The device has a simple mechanical design that allows a user to indicate his virtual navigation intentions by leaning accordingly. We also propose a control law inspired by the biomechanics of the human locomotion to transform the measured leaning angle into a walking direction and speed - i.e., a virtual velocity vector. A preliminary evaluation was conducted in order to evaluate the advantages and drawbacks of the proposed interface and to better draw the future expectations of such a device.

Walking in a Cube: Novel Metaphors for Safely Navigating Large Virtual Environments in Restricted Real Workspaces

Abstract: Immersive spaces such as 4-sided displays with stereo viewing and high-quality tracking provide a very engaging and realistic virtual experience. However, walking is inherently limited by the restricted physical space, both due to the screens (limited translation) and the missing back screen (limited rotation). In this paper, we propose three novel locomotion techniques that have three concurrent goals: keep the user safe from reaching the translational and rotational boundaries; increase the amount of real walking and finally, provide a more enjoyable and ecological interaction paradigm compared to traditional controller-based approaches. We notably introduce the "Virtual Companion", which uses a small bird to guide the user through VEs larger than the physical space. We evaluate the three new techniques through a user study with travel-to-target and path following tasks. The study provides insight into the relative strengths of each new technique for the three aforementioned goals. Specifically, if speed and accuracy are paramount, traditional controller interfaces augmented with our novel warning techniques may be more appropriate; if physical walking is more important, two of our paradigms (extended Magic Barrier Tape and Constrained Wand) should be preferred; last, fun and ecological criteria would favor the Virtual Companion.

The Perception of the Visual World. By James J. Gibson. U.S.A.: Houghton Mifflin Company, 1950 (George Allen & Unwin, Ltd., London). Price 35s.

Abstract: Let's read! We will often find out this sentence everywhere. When still being a kid, mom used to order us to always read, so did the teacher. Some books are fully read in a week and we need the obligation to support reading. What about now? Do you still love reading? Is reading only for you who have obligation? Absolutely not! We here offer you a new book enPDFd the perception of the visual world to read.

Robot vision

Abstract: A scheme is developed for classifying the types of motion perceived by a humanlike robot. It is assumed that the robot receives visual images of the scene using a perspective system model. Equations, theorems, concepts, clues, etc., relating the objects, their positions, and their motion to their images on the focal plane are presented. >

Review on cybersickness in applications and visual displays

Abstract: Cybersickness is an affliction common to users of virtual environments. Similar in symptoms to motion sickness, cybersickness can result in nausea, headaches, and dizziness. With these systems becoming readily available to the general public, reports of cybersickness have increased and there is a growing concern about the safety of these systems. This review presents the current state of research methods, theories, and known aspects associated with cybersickness. Current measurements of incidence of cybersickness are questionnaires, postural sway, and physiological state. Varying effects due to display and rendering modes, such as visual display type and stereoscopic or monoscopic rendering, are compared. The known and suspected application aspects that induce cybersickness are discussed. There are numerous potential contributing application design aspects, many of which have had limited study, but field of view and navigation are strongly correlated with cybersickness. The effect of visual displays is not well understood, and application design may be of greater importance.