Guillaume Moreau

Ecole Centrale de Nantes | EC Nantes · Department of Computer Science and Mathematics

Immersive geospatial visualization finds increasing application for navigation, exploration, and analysis. Many such require the display of data at different scales, often in views with three-dimensional geometry. Multi-view solutions, such as focus+context, overview+detail, and distorted projections can show different scales at the same time, and...

Wind can influence people’s behavior and their way of inhabiting an architectural or urban space. Furthermore, virtual reality (VR) enables the simulation of different physical and sensitive phenomena such as the wind. We aim to analyze the effects of different wind representations in terms of perception of its properties and sense of presence in V...

Technological developments provide solutions to alleviate the tremendous impact on the health and autonomy due to the impact of dementia on navigation abilities. We systematically reviewed the literature on devices tested to provide assistance to people with dementia during indoor, outdoor and virtual navigation (PROSPERO ID number: 215585). Medlin...

Augmented reality (AR) is an emerging technology that is applied in many fields. One of the limitations that still prevents AR to be even more widely used relates to the accessibility of devices. Indeed, the devices currently used are usually high end, expensive glasses or mobile devices. vSLAM (visual simultaneous localization and mapping) algorit...

The set of physical and sensitive phenomena that interacts with the urban morphology acts on the resulting perception from the users of a place. Its study and representation provides elements beyond the aesthetics aspects that can allow a better understanding of the space and future urban projects. We aim to analyze the effects of three different w...

Commonly used Head Mounted Displays (HMDs) in Augmented Reality (AR), namely Optical See-Through (OST) displays, suffer from a main drawback: their focal lenses can only provide a fixed focal distance. Such a limitation is suspected to be one of the main factors for distance misperception in AR. In this paper, we studied the use of an emerging new...

Virtual reality (VR) headsets offer a large and immersive workspace for displaying visualizations with stereoscopic vision, as compared to traditional environments with monitors or printouts. The controllers for these devices further allow direct three-dimensional interaction with the virtual environment. In this paper, we make use of these advanta...

The application of virtual reality in human activities has been rapidly growing during the last decade. Shopping for food is an important part of people's daily lives. As overnight delivery services of fresh produce, such as Amazon Fresh, are in their development stage, more studies on virtual stores for perishable products are needed because the q...

This paper focuses on how virtual objects' shadows as well as differences in alignment between virtual and real lighting influence distance perception in optical see‐through (OST) augmented reality (AR). Four hypotheses are proposed: (H1) Participants underestimate distances in OST AR; (H2) Virtual objects' shadows improve distance judgment accurac...

This study investigates the effects of fruits and vegetables (FaVs) abnormality on consumer perceptions and purchasing behavior. For the purposes of the study, a virtual grocery store was created with a fresh FaVs section, where 142 participants became immersed using an Oculus Rift DK2 Head-Mounted Display (HMD) software. Participants were presente...

With the recent growth in the development of augmented reality (AR) technologies, it is becoming important to study human perception of AR scenes. In order to detect whether users will suffer more from visual and operator fatigue when watching virtual objects through optical see‐through head‐mounted displays (OST‐HMDs), compared with watching real...

This research investigates consumers’ reactions (perceptions and purchasing behavior) in store to misshapen fruits and vegetables. Given its objectives and the specificities of the products studied, it uses a virtual store, coupled with a new technology, the virtual reality headset (Oculus Rift). The results obtained enrich those of the recent pion...

L’article construit une articulation des notions d’écosystème de représentations, d’apprentissage et de conception. Le modèle descriptif proposé permet d’interroger l’impact d’une altération de l’écosystème de représentations sur l’apprentissage de la conception en studio de projet. Deux écosystèmes utilisant des techniques de Réalité Virtuelle pou...

Research in Virtual Reality (VR) showed that embodiment can influence participants' perceptions and behavior when embodied in a different yet plausible virtual body. In this paper, we study the changes an obese virtual body has on products perception (e.g., taste, etc.) and purchase behavior (e.g., number purchased) in an immersive virtual retail s...

Design studio critiques are key moments for students' learning and designing processes. During critiques, the representational ecosystem provides a setting for the critique to unfold. Tutors and students, while presenting and discussing students' designs, interact with each other and the representational ecosystem. In this article, a case study ill...

This chapter discusses the topics for which solutions exist, but which still pose scientific challenges and elements of complexity which would be helpful to discuss in detail. It describes physical models to detect collisions and the problem of the virtual human. The chapter then examines naturalness of the interaction, and proposes an analysis of...

This chapter provides an overview of the current state of augmented reality (AR). It examines the questions of pose computation, which could be used to locate a user in an immersive room or to model the real world, interactions in AR, and the concept of presence in environments that combine real and virtual elements. The chapter describes important...

Virtual and Augmented Reality have existed for a long time but were stuck to the research world or to some large manufacturing companies. With the appearance of low-cost devices, it is expected a number of new applications, including for the general audience. This book aims at making a statement about those novelties as well as distinguishing them...

Image geolocalization has become an important research field during the last decade. This field is divided into two main sections. The first is image geolocalization that is used to find out which country, region or city the image belongs to. The second one is refining image localization for uses that require more accuracy such as augmented reality...

Virtual Reality and Augmented Reality research in the architecture field show a variety of possible uses of systems to accompany designers, laymen and decision makers in their architectural design process. This article provides a survey of VR and AR devices among a corpus of papers selected from conferences and journals on CAAD (Computer Aided Arch...

In desktop 3D modeling applications, object manipulation relies on the use of standard transformation widgets. However, these widgets are less efficient on touchscreens due to the low accuracy of touch inputs, and also to the fingertip occlusion issue. In this paper, we propose two unimanual constrained manipulation techniques on TabletPCs. Based o...

We present a fast and accurate method for reconstructing surfaces of revolution (SoR) on 3D data and its application to structural modeling of a cluttered scene in real-time. To estimate a SoR axis, we derive an approximately linear cost function for fast convergence. Also, we design a framework for reconstructing SoR on dense SLAM. In the experime...

To make constrained manipulation of 3D objects in desktop 3D applications, 3D transformation widgets are commonly used. However, their performance degrades on touchscreens because of low accuracy of touch inputs and the fingertip occlusion problem. In this paper, we present TouchSketch, a touch-based interface which allows users to perform independ...

In this paper, we introduce LayerStroke, a new touch-based selection technique for small targets located in a dense cluster. This technique aims to reduce the cluster density by dividing the targets space into different layers. To select a target, users can first select a layer by drawing a stroke on the screen. After that, targets inside the selec...

Les informations temporelles jouent un rôle important dans une grande majorité de problèmes scientifiques. En géographie, l'interaction avec les aspects spatiaux et la référence à des calendriers sur de longues périodes est fréquente. Les approches théoriques ou expérimentales croisent nécessairement différents points de vue de plusieurs communauté...

We present a method which can quickly and robustly match 2D and 3D point patterns based on their sole spatial distribution, but it can also handle other cues if available. This method can be easily adapted to many transformations such as similarity transformations in 2D/3D, and affine and perspective transformations in 2D. It is based on local geom...

Virtual reality is a good tool to design and assess urban projects and to study perception in cities. Climate perception significantly influences the perception and use of urban spaces, however, virtual urban environments are scarcely represented with different climatic aspects. In this paper, we study the role that visual cues (sky aspect, shadows...

This paper presents our recent research on augmented maps where unprepared paper maps are used and Geographic Information System serves both as reference database and augmentation data. We use road intersections to register paper map and GIS so several paper maps of the same city whatever their styles and colors can be augmented using the same refe...

This paper presents a method to detect and track a paper map and overlay virtual data over it. First, we take a picture of the map and identify the road colors using our road area extraction method. Using the color information we can then extract in real time the roads from a video and use the position of the intersections to identify the map from...

Augmented maps have many important applications. However, no mature registration method exists to associate unprepared maps with a Geographical Information System (GIS) database which would be used to superimpose simulation results or route display on a paper map. In this paper, we propose a method called Robust Random Dot Markers (RRDM) that can r...

Thanks to immersion and interaction, Virtual Reality (VR) offers a shift of paradigm compared to traditional computer graphics or simulation software. Most VR applications include a visual rendering part. However, efficient and relevant visual interfacing of a human user (who can be a designer, the final user of a future product, a trainee or the s...

One of the main issues for authorities in disaster management is to build clear situation awareness that is consistent and accurate in both space and time. Authorities usually have Geographical Information Systems (GIS) for reference data. One current trend of GIS is the use of crowd sourcing, i.e. gather information from the public to build very l...

Encyclopedic knowledge bases can be powerful tools for the acquisition of fundamental knowledge for learners. However, the structure and the very nature of these documents can impede learning processes. By extracting domain ontologies from reference books and using this same material to populate an intelligent learning system, we propose a methodol...

Considering sustainable development of cities implies investigating cities in a holistic way taking into account many interrelations between various urban or environmental issues. 3D city models are increasingly used in different cities and countries for an intended wide range of applications beyond mere visualization. Could these 3D City models be...

Immersive Virtual Reality (VR) systems offer vast opportunities in terms of scientific research as well as in terms of industrial applications. Typical industrial applications include 3D design, er-gonomics and training. Although such VR systems have proven to be of great interest for companies and research institutes, their construction and mainte...

Virtual reality thanks to immersion and interaction is a good tool to assess urban environments. Allowing users to freely navigate in the virtual environment, virtual reality permits to take into account the influence of dynamic elements and the observers’ actions in the perception of urban spaces. However, previous works have shown that virtual as...

For applications such as outdoor Augmented Reality (AR) or 3D City Model construction of updating, a real-time registration between a video sequence and a Geographic Information System (GIS) is required. In this work, we present a registration system using a GPS prior and a skyline matching method to estimate the camera pose from images. A skyline...

Climatic effects represent the physical signals (temperature, wind, humidity, light) which can have a perceptual impact for human-beings. They significantly influence perception and use of urban spaces. Nevertheless, while virtual environments have been proven as good tools to assess urban projects by non-expert people or to study perception in cit...

This paper presents two spatial query methods for a Geographic Information System (GIS) that runs on a touch screen. On conventional GIS interfaces SQL is used to construct spatial queries. However keyboard typing proves to be inefficient on touch screens. Furthermore, SQL is not an easy-learning language, especially for novices to GIS. To simplify...

Reference books and encyclopedic knowledge bases present learners with an important source of fundamental concepts. However, the resulting knowledge acquisition process is often hindered by the linearity that is inherent to these resources, making it difficult for learners to realize the many links that exist between these concepts. This research p...

Density is probably one of the most used indicators to characterize urban development. Even if it is a quantitative and properly defined measure, there are still problems to use it properly. This paper proposes a renewed approach to characterize urban density based on buildings' footprints. It can be applied on huge datasets and allows multi-level...

In order to enable multi-scale urban visualization, multiple model representations at different levels of detail (LoDs) need to be produced (like by generalization) in advance or on the fly. At local scale, building groups are involved and at least medium LoD is needed in terms of visual perception. Motivated by such demands, this article proposes...

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...

Camera pose estimation from an image has long been a very active research for Video/GIS registration. Different from traditional methods which are based on direct building feature matching, this paper presents an alternative method which uses an overall Skyline feature to determine the camera’s orientation. Through our skyline matching method we fi...

Although information modeling techniques and ontologies developments have been intensively used and studied, we believe that clear and logical links between these different concepts are missing. It is even more crucial in 3D city modeling context where standardization processes are less developed. In this paper, we first give an unambiguous view of...