Publications by Ronan Boulic | EPFL Graph Search

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Realistic mechanical models of biological soft tissues are a key issue to allow the implementation of reliable systems to aid on orthopedic diagnosis and surgery planning. We are working to develop a computerized soft tissues model for biotissues based on a mass-spring-like approach. We present several experiments towards the parameterization of our model from the elastic properties of real materials

Optical motion capture provides an impressive ability to replicate gestures. However, even with a highly professional system there are many instances where crucial markers are occluded or when the algorithm confuses the trajectory of one marker with that of another. This requires much editing work on the part of the animator before the virtual characters are ready for their screen debuts. In this paper, we present an approach to increasing the robustness of a motion capture system by using a sophisticated a

The manipulation of a virtual object by means of a digital glove is a tedious task for repetitive position and orientation adjustments. We try to overcome the lack of force feedback of general purpose digital gloves. We propose a solution based only on the interpretation of instantaneous hand posture variations. From this knowledge, a virtual contact model analog to the Coulomb law allows to evaluate the instantaneous nature of the contact, firm or sliding, between virtual sensors attached to the fingers an

Cybersickness induced through Virtual Reality (VR) applications is still one of its main barriers as it can induce unwanted side-effects in players, significantly hindering the overall experience. Despite the wealth of research available on this topic, it ...

Presents an interactive tool dedicated to the design of walking trajectories for human figures. It uses a global human free-walking model built from experimental data on a wide range of normalized velocities. This tool is particularly efficient in that the higher level of the walking model works independently from the effective play of the low level joint trajectories by the figure. This independence is gained by means of a transfer function calibrating the figure's normalized velocity with respect to the t

This paper explores the issue of interactive low-dimensional human motion synthesis. We compare the performances of two motion models, i.e. Principal Components Analysis (PCA) or Probabilistic PCA (PPCA), for solving a constrained optimization problem with ...

Studies of cybersickness (CS) often require a significant invest- ment in creating the primary VR environment and other experiment- related features. In addition, minor differences in VR content in independent studies may lead to opposite results. This mot ...

Today, to create and to simulate a virtual anatomical version of a subject is useful in the decision process of surgical treatments. The muscular activity is one of the factors which can contribute to abnormal movements such as in spasticity or static cont ...

Proposes a general framework to enhance grasping interactions of an operator wearing a digital glove. The authors focus on a consistent interpretation of the posture information acquired with the glove in order to reflect the grasp of virtual artifacts. This allows higher skill manipulations in virtual environments and also improves interactions with virtual human models. A handshake case-study highlights the application range of this methodology.

In this paper we present an intuitive tool suitable for 2D artists using touch-enabled pen tablets. An artist-oriented tool should be easy-to-use, real-time, versatile, and locally refinable. Our approach uses an interactive system for 3D character posing ...

The scope of this paper is to propose a system for the automatic derivation of a human curved walking trajectory from the analysis provided by its synthetic vision module. The study context is a planar environment with still and sparse foothold locations. A general methodology associates the two low-level modules of vision and walking with a planification module which establishes the middle term path from the knowledge of the visualized environment. The planification is made under the constraint of minimizi

Third Person Perspective (3PP) viewpoints have the potential to expand how one perceives and acts in a virtual environment. They offer increased awareness of the posture and of the surrounding of the virtual body as compared to First Person Perspective (1P ...

Providing Virtual Reality(VR) users with a 3D representation of their body complements the experience of immersion and presence in the virtual world with the experience of being physically located and more personally involved. A full-body avatar representa ...

We extend a recent approach for the position control of the center of mass for any tree structured articulated figure in a multiple support context. Our approach fits into existing high level interfaces of behavioral control of human figures; it brings the necessary realism for static positioning according to the mass distribution of the figure. The single support case is first recalled prior to the presentation of the mass distribution partitioning and the general case of multiple support. Simulations of 3

We present an animation interface designed to conveniently control the motion capture process. The transition of performer's hand gestures tracked by a dataglove is recognized for software remote control. An intuitive camera metaphor allows one to specify the viewpoint location using the magnetic sensors strapped to the performer's head. The human motion capture is based on the Anatomical Converter, a toolkit to convert sensor measurements into human anatomical rotations in real time. An improved human moti

We investigate how the movement measurement technologies developed for virtual reality applications can be applied to track in real-time the full body posture of a human being. The accuracy of this information is of definite importance to evaluate the feasibility of complex tasks involving human beings. We present a full body movement measurement approach. It provides a realistic conversion in real-time with a reasonable number of sensors. Associated with the hand movement measurement and correction algorit

We present an image-based rendering technique to represent virtual humans in real-time. Though we deal only with virtual humans, the concept can be applied to any articulated character. Our technique is termed animated impostors because it extends the notion of dynamic impostors to take into account changes in the character's appearance. We also show how impostors can be embedded into large-scale simulations/applications

In this paper, we present a case study using a spreadsheet-like interface for exploring biomedical datasets generated by a biomechanical model of the hip. The case we analyze here is an osteotomy corrective surgery that reorients the femoral body in relation to the femoral neck, somewhat like the intertrochanteric osteotomy described by Imhäuser (2). That is a procedure recommended by most authors as a surgical treatment of severe slipped capital femoral epiphysis. Then we compare estimated contact area of

In this paper we evaluate the use of non-planar projections as a means to increase the Field of View (FoV) in embodied Virtual Reality (VR). Our main goal is to bring the virtual body into the user’s FoV and to understand how this affects the virtual body/ ...

Due to its intrinsic complexity. full-body postural input has been Mostly limited to off-line motion capture and to on-line Puppetry of a virtual character with little interaction with its environment (e.g. floor). The motion capture technology is now matu ...

Ronan Boulic

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Deformable tissue parameterized by properties of real biological tissue

Skeleton-based motion capture for robust reconstruction of human motion

Multi-finger manipulation of virtual objects

Eye Thought You Were Sick! Exploring Eye Behaviors for Cybersickness Detection in VR

An interactive tool for the design of human free-walking trajectories

Interactive Low-Dimensional Human Motion Synthesis by Combining Motion Models and PIK

Cybersickness assessment framework(CSAF): An Open Source Repository for Standardized Cybersickness Experiments

A subject-specific software solution for the modeling and the visualization of muscles deformations

Consistent Grasping Interactions with Virtual Actors Based on the Multi-sensor Hand Model

Artist-Oriented 3D Character Posing from 2D Strokes

Automatic derivation of curved human walking trajectories from synthetic vision

Characterizing Embodied Interaction in First and Third Person Perspective Viewpoints

Reaching articular limits can negatively impact embodiment in virtual reality

Position control of the center of mass for articulated figures in multiple support

An animation interface designed for motion capture

An architecture for immersive evaluation of complex human tasks

Lowering the cost of virtual human rendering with structured animated impostors

Stress Distribution Visualization on Pre- and Post-Operative Virtual Hip Joint

Embodied interaction using non-planar projections in immersive virtual reality

On scaling strategies for the full-body postural control of virtual mannequins