Alexis Paljic

• PhD, HDR
• Mines Paris, PSL University

Several recent works have presented image-based methods for creating high-fidelity immersive virtual environments from photographs of real-world scenes. In this paper, we provide a user-centered evaluation of such methods by way of a user study investigating their impact on viewers’ perception of visual realism and sense of presence. In particular,...

The release of consumer-grade head-mounted displays has helped bring virtual reality (VR) to our homes, cultural sites, and workplaces, increasingly making it a part of our everyday lives. In response, many content creators have expressed renewed interest in bringing the people, objects, and places of our daily lives into VR, helping push the bound...

This demonstration showcases an open-source toolkit we developed in the Unity game engine to enable authors to render real-world photographs in virtual reality (VR) with motion parallax and view-dependent highlights. First, we illustrate the toolset's capabilities by using it to display interactive, photorealistic renderings of a museum's mineral c...

From image-based virtual tours of apartments to digital museum exhibits, transforming photographs of real-world scenes into visually faithful virtual environments has many applications. In this paper, we present our development of a toolkit that places recent advances in the field of image-based rendering (IBR) into the hands of virtual reality (VR...

This video submission illustrates the Core Open Lab on Image-Based Rendering Innovation for Virtual Reality (COLIBRI VR), an open-source toolkit we developed to help authors render photographs of real-world people, objects, and places as responsive 3D assets in VR. We integrated COLIBRI VR as a package for the Unity game engine: in this way, the to...

This book constitutes thoroughly revised and selected papers from the 14th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, VISIGRAPP 2019, held in Prague, Czech Republic, in February 2019. The 25 thoroughly revised and extended papers presented in this volume were carefully reviewed and sele...

Creating lifelike virtual humans for interactive virtual reality is a difficult task. Most current solutions rely either on crafting synthetic character models and animations, or on capturing real people with complex camera setups. As an alternative, we propose leveraging efficient learning-based models for human mesh estimation, and applying them...

This work addresses the problem of using real-world data captured from a single viewpoint by a low-cost 360-degree camera to create an immersive and interactive virtual reality scene. We combine different existing state-of-the-art data enhancement methods based on pre-trained deep learning models to quickly and automatically obtain 3D scenes with a...

Driver interaction with increasingly automated vehicles requires prior knowledge of system capabilities, operational know-how to use novel car equipment and responsiveness to unpredictable situations. With the purpose of getting drivers ready for autonomous driving, in a between-subject study sixty inexperienced participants were trained with an on...

Complementary advances in the fields of virtual reality (VR) and reality capture have led to a growing demand for VR experiences that enable users to convincingly move around in an environment created from a real-world scene. Most methods address this issue by first acquiring a large number of image samples from different viewpoints. However, this...

In conditionally automated vehicles, drivers can engage in secondary activities while traveling to their destination. However, drivers are required to appropriately respond, in a limited amount of time, to a take-over request when the system reaches its functional boundaries. Interacting with the car in the proper way from the first ride is crucial...

In conditionally automated vehicles, drivers can engage in secondary activities while traveling to their destination. However, drivers are required to appropriately respond, in a limited amount of time, to a take-over request when the system reaches its functional boundaries. In this context, Virtual Reality systems represent a promising training a...

This paper presents a preliminary study of the use of Virtual Reality for the simulation of a particular driving task: the control recovery of a semi-autonomous vehicle by a driver engaged in an attention-demanding secondary activity. In this paper the authors describe a fully immersive simulator for semi-autonomous vehicles and present the pilot s...

This work was conducted in the context of perceptually realistic image simulations of paint materials. These simulations aim at producing the same visual response in an observer as real objects given certain illumination and observation conditions. The colorimetric validation ensures that the colors in the simulated images differ from the real scen...

Thanks to improvements of the last decades in the robotic field, small Unmanned Aerial Vehicle (sUAV) have become efficient remote sensors for infantrymen on the battlefield. Their increasing mobility and autonomy allow acquiring essential strategic information in a constantly evolving environment. However, due to the hostile nature of the battlefi...

The assessment of images of complex materials on an absolute scale is difficult for a human observer. Comparing physical and virtual samples side-by-side simplifies the task by introducing a reference. The goal of this article is to study the influence of image exposure on the perception of realism on images of paint materials containing sparkling...

The context of this work is predictive rendering; our objective is to previsualize materials based on physical models within computer graphics simulations. In this work we focus on paints constituted of metallic flakes within a dielectric binder. We want to validate a "virtual material workshop" approach, where a user could change the composition a...

This paper deals with the design and the evaluation of human-like robot movements. Three criteria were proposed and evaluated regarding their impact on the human-likeness of the robot movements: the inertia of the base, the inertia of the end-effector and the velocity profile. A specific tool was designed to generate different levels of anthropo-mo...

In the context of using an Unmanned Aerial Vehicle (UAV) in hostile environments, gestures allow to free the operator of bulky control interfaces. Since a navigation plan is defined before the mission, only a few commands have to be activated during the mission. This allows a gestural symbolic interaction that maps commands to a set of gestures. Ne...

Predictive rendering of material appearance means going deep into the understanding of the physical interaction between light and matter and how these interactions are perceived by the human brain. In this paper we describe our approach to predict the appearance of composite materials by relying on the multi-scale nature of the involved phenomena....

This work is performed as part of the perceptual validation stage in the stereoscopic visualization of computer- generated (CG) images of materials --typically car paints-- containing sparkling metallic flakes. The perceived material aspect is closely linked to the flake density, depth, and sparkling; in turn, our perception of an image of said mat...

This paper focuses on the acceptability of human-robot collaboration in industrial environments. A use case was designed in which an operator and a robot had to work side-by-side on automotive assembly lines, with different levels of co-presence. This use case was implemented both in a physical and in a virtual situation using virtual reality. A us...

The present work studies the role of stereoscopy on perceived surface aspect of computer generated complex materials. The objective is to investigate if, and how, the additional information conveyed by the binocular vision affects the observer judgment on the evaluation of flake density in an effect paint simulation. We have set up a heuristic flak...

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...

Robots are becoming more and more present in our everyday life: they are already used for domestic tasks, for companionship activities, and soon they will be used to assist humans and collaborate with them in their work. Human-robot collaboration has already been studied in the industry, for ergonomics and efficiency purposes, but more from a safet...

In this paper we study the memorization of user created gestures for 3DUI. Wide public applications mostly use standardized gestures for interactions with simple contents. This work is motivated by two application cases for which a standardized approach is not possible and thus user specific or dedicated interfaces are needed. The first one is appl...

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...

In this paper we evaluate one interaction method and four display techniques for exploring volumetric datasets in virtual reality immersive environments. We propose an approach based on the display of a subset of the volumetric data, as isosurfaces, and an interactive manipulation of the isosurfaces to allow the user to look for local feature in th...

This poster presents a novel approach for integrating, as insets, high resolution stereoscopic areas within a wider low resolution stereoscopic image. The objective is to propose ways to increase local resolution in virtual reality systems, with the use of a small number of additional projectors. Our novel approach consists of inserting high resolu...

In this paper, we introduce a new deformation method adapted to immersive design. The use of Virtual Reality (VR) in the design process implies a physical displacement of project actors and data between the virtual reality facilities and the design office. The decisions taken in the immersive environment are manually reflected on the Computed Aided...

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...

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...

Nous présentons dans cet article des travaux préparatoires au Projet IHS 10 sur une méthode exploitant conjointement les ressources de la réalité virtuelle et de la CAO. L'objectif est l'amélioration de la productivité du concepteur, particulièrement dans le domaine automobile. Cet article expose une première approche axée sur l'utilisation d'un li...

Le retour d’effort permet de renvoyer à un utilisateur des informations relatives au sens du toucher. Ces travaux s’intéressent aux retours d’effort passifs, n’apportant pas d’énergie mécanique à l’utilisateur, ainsi qu’à la distance de manipulation en environnements immersifs. Nous proposons et évaluons des méthodes de retour d’effort passif dont...

In this work, we investigate whether pseudo-haptic feedback is suitable for simulating torque feedback. Pseudo-haptic feedback is based on the coupling of visual feedback and the internal resistance of an input device which passively reacts to the user's applied force. An experiment was conducted to evaluate this feedback and compare isometric and...

Virtual environments such as the Responsive WorkbenchTM1 allow the close manipulation of virtual objects. We define close manipulation as either direct ma- nipulation or manipulation at a relatively small distance. This paper reports on two studies on close manipulation us- ing the Responsive Workbench. The first study investigates the influence of...

In this paper a novel haptic interface is presented to enable human-operators to "feel" and intuitively mirror the stiffness/forces at remote/virtual sites enabling control of robots as human -surrogates. The proposed haptic interface is intended to provide human operators intuitive feeling of the stiffness and forces at remote or virtual sites in...

For many years, the robotic community sought to develop robots that can eventually operate autonomously and eliminate the need for human operators. However, there is an increasing realization that there are some tasks that human can perform significantly better but, due to associated hazards, distance, physical limitations and other causes, only ro...

We propose a passive haptic feedback system that can pro-vide the user with grounded forces in a 3D manipulation space. A vi-sual/haptic interaction is used to control forces returned by the system, which is composed of cables and a braking system. An experiment, con-sisting of two sessions of stickiness comparison tasks, is conducted to evaluate t...