Xavier Granier

Xavier Granier
Institut d'Optique Graduate School · Laboratoire Photonique, Numerique, Nanosciences (LP2N)

Eng; MS; PhD; HDR

About

123
Publications
13,168
Reads
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1,035
Citations
Citations since 2016
46 Research Items
438 Citations
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20162017201820192020202120220204060
Introduction
My main research background is realistic rendering and global illumination. I have extended his interest to acquisition and modeling of material properties and light sources (at University of British Columbia - Vancouver - Canada), sketching interactions (with Zheijiang University - Hangzhou - China) and expressive rendering (previously called non-photorealistic rendering). Currently, the main focus of my research is the accurate simulation of optical phenomena and the creation of new technologies that combine the strengths of optics and computer graphics. I mainly consider impacts of 3D technologies as tools for studies, preservation and diffusion of Cultural Heritage.
Additional affiliations
December 2012 - September 2019
Institut d'Optique Graduate School
Position
  • Professor (Full)
January 2012 - September 2018
INRIA, University of Bordeaux, Insitut d'Optique Graduate School, CNRS
Position
  • Head of Department
December 2001 - August 2003
University of British Columbia - Vancouver
Position
  • PostDoc Position
Education
September 1998 - November 2001
University Joseph Fourier - Grenoble 1
Field of study
  • Computer Graphics
September 1997 - August 1998
University Joseph Fourier - Grenoble 1
Field of study
  • Computer Graphics; Computer Vision
September 1995 - August 1998
ENSIMAG
Field of study
  • Computer Sciences; Computer Graphics; Computer Vision; Numerical Techniques

Publications

Publications (123)
Preprint
Full-text available
We introduce the French National 3D Data Repository for Humanities designed for the conservation and the publication of 3D research data in the field of Humanities and Social Sciences. We present the choices made for the data organization, metadata, standards and infrastructure towards a FAIR service. With 437 references at the time of the writing,...
Article
This paper discusses the use of a small ultraportable hyperspectral camera in the VIS-NIR (Visible-Near Infrared) range for archaeological fieldwork and its hardware, data processing workflows, and spectral information that can be used for in situ screening. Hyperspectral imaging is a widespread, non-destructive analytical technique used in various...
Article
Glazed ceramics are a common material analyzed through geochemistry, whether in the form of tableware collected during excavations or tiles observed as part of architectural features. Within the framework of these studies, measuring the thickness of the transparent glaze is one of the useful variables available for the characterization of the ceram...
Article
Full-text available
Nanostructured materials have recently emerged as a promising approach for material appearance design. Research has mainly focused on creating structural colours by wave interference, leaving aside other important aspects that constitute the visual appearance of an object, such as the respective weight of specular and diffuse reflectances, object m...
Article
3D Geographical Information Systems (GIS), Building Information Modeling (BIM),... These words are increasingly used for Cultural Heritage studies to refer to the necessity to connect heterogeneous data with a 3D model. In this paper, we introduce and formalize the notion of ”Referenced Information System in 3D” - RIS3D, which extends the concept o...
Preprint
Full-text available
Nanostructured materials have recently emerged as a promising approach for material appearance design. Research has been focused so far on creating structural colours by wave interference, unfortunately leaving aside many of the important aspects that constitute the visual appearance of an object, like the respective weight of specular and diffuse...
Conference Paper
3D restitution is now a well-known tool to validate hypotheses on historical buildings that do not exist anymore. The present project takes the method a step further in order to explore the art historical topic of ornament reuse in 19th century revival architecture, particularly in Cairo. The case study is the Saint-Maurice residence, built 1875-79...
Conference Paper
We introduce the French National 3D Data Repository for Humanities, designed for the conservation and the publication of 3D research data in the field of Humanities and Social Sciences. We present the choices made for the data organization, metadata, standards and infrastructure towards a FAIR service. With 419 references at the time of the writing...
Technical Report
This document is the result of an ongoing effort to enable SSH and 3D actors to interact around a common vocabulary. This lexicon is intended to accompany the various deliverables of the 3D consortium. It is also intended to help enrich TaDiRAH, the "Taxonomy of Digital Research Activities in the Humanities" of the European DARIAH consortium. This...
Technical Report
As part of the activities of Huma-Num’s Consortium 3D for the Humanities, many meetings have taken place, bringing together scientists from various fields (historians, archaeologists, computer sciences, architects, 3D engineers, archivists, etc.) with the aim of providing effective solutions for the creation and usage of 3D digital models in the Hu...
Patent
Un dispositif optique comprend un guide d’onde transparent, présentant une première portion d’expansion ; une deuxième portion d’expansion, reliée à la première portion d’expansion, la deuxième portion d’expansion comprend une zone de sortie de guide ; une source de rayonnements lumineux comprenant au moins deux sources lumineuses dirigées de maniè...
Article
Nous vivons une époque où les données numérisées et numériques sont de plus en plus un support des travaux de recherches. Avec la promotion de la science ouverte, se pose dès lors la question de la transmission de ces données pour la reproductibilité des résultats et la continuité des travaux. Il est donc plus que nécessaire de fournir un service a...
Conference Paper
Fast computation of light propagation using Monte Carlo techniques requires finding the best samples from the space of light paths. For the last 30 years, numerous strategies have been developed to address this problem but choosing the best one is really scene-dependent. Multiple Importance Sampling (MIS) emerges as a potential generic solution by...
Conference Paper
Que faire, que FAIR de ses données 3D une fois un projet de recherche terminé? Comment assurer leur pérennisation? Désormais, le chercheur en SHS qui produit au sein de son projet de recherche un résultat en trois dimensions (restitution, modélisation) dispose d’un outil pour le stocker de manière pérenne, et cela dans le respect des principes fond...
Poster
Le Consortium 3D SHS, labellisé en 2014 puis en 2018 par la TGIR Huma-Num, a pour vocation de fédérer les initiatives foisonnantes autour de la 3D pour les Sciences Humaines et Sociales pour définir des standards et des recommandations d'usage ainsi que pour mettre en place des outils répondants aux besoins des chercheurs. Il regroupe un nombre cro...
Book
La multiplication des initiatives autour de la création, des usages et de la conservation des données 3D dans les sciences humaines et sociales montrent une réelle nécessitée de se coordonner afin de définir des standards dans les usages, les méthodologies, les formats. C'est dans ce but qu'a été créé le consortium 3D SHS sous l'égide de la TGIR Hu...
Article
We present a novel transparent autostereoscopic display consisting of laser picoprojectors, a wedge light guide, and a holographic optical element. The holographic optical element is optically recorded, and we present the recording setup, our prototype, as well as the results. Such a display can superimpose 3D data on the real world without any wea...
Poster
Les objectifs Le projet vise à développer une nouvelle vision de la 3D pour le patrimoine monumental afin de répondre à la fois aux questionnements en histoire de l'art par l'incorporation d'une information visuelle enrichie, et aux nécessités de validation scientifique en étant support d'agrégation des données historiques mobilisées pour les resti...
Article
A focused plenoptic camera has the ability to record and separate spatial and directional information of the incoming light. Combined with the appropriate algorithm, a 3D scene could be reconstructed from a single acquisition, over a depth range called plenoptic depth-of-field. In this Letter, we study the contrast variations with depth as a way to...
Poster
The 3D Consortium of the TGIR Huma-Num has been created based on the observation that there are many initiatives around 3D for the Digital Humanities without real coordination between them. The proliferation of initiatives makes the task difficult and only a consortium-type organization can bring together forces in order to define standardized solu...
Conference Paper
Knowledge production has always act globally, and when it comes to the humanities early networks of scholars can still be traced in their letter correspondence. With the emergence of digital humanities more prominently in the 1970s, research communities have organized themselves in many different ways. The enthusiasm generated by the promises of wh...
Article
Acquiring images of archaeological artifacts is an essential step for the study and preservation of cultural heritage. In constrained environments, traditional acquisition techniques may fail or be too invasive. We present an optical device including a camera and a wedge waveguide that is optimized for imaging within confined spaces in archeology....
Conference Paper
We present a novel transparent autostereoscopic display consisting of laser picoprojectors, a wedge light guide and a holographic optical element. Such a display can superimpose 3D data on the real world without any wearables.
Poster
A plenoptic camera allows to acquire and separate spatial and directional information of the light coming from a scene. It allows applications such as refocusing at different depths from the one where the image has been acquired. In the literature, different refocusing algorithms are presented for several optical plenoptic configurations. We have p...
Presentation
À travers les expériences des usages de la 3D au service des sciences humaines et sociales, recensées par le Consortium 3D pour les SHS, et celles effectuées par Archeovision, nous illustrerons que la 3D permet de - Travailler ensemble au-delà des expériences, des cultures scientifiques et disciplinaires différentes, ceci de part le fait que la 3D...
Poster
aLTAG3D est un logiciel libre développé par le Consortium 3D SHS pour la génération d'archive à long terme de projets 3D compatible avec les services du CINES. http://altag3d.huma-num.fr/ Archivage des donnés 3D et métadonnées au CINES
Technical Report
Dans le cadre des activités du Consortium 3D de la TGIR Huma-Num, de nombreuses rencontres ont eu lieu réunissant des spécialistes aux profils divers (historiens, archéologues, informaticiens, architectes, ingénieurs 3D, archivistes …etc.) afin de proposer des solutions aux problématiques liées à la 3D en sciences humaines et sociales. Une des miss...
Technical Report
Ce document est le résultat d’un effort continu pour permettre aux acteurs des SHS et ceux de la 3D d’interagir autour d’un vocabulaire commun. Ce lexique a pour but d’accompagner les différents livrables du consortium 3D. Il a aussi vocation à terme à aider à l’enrichissement de TaDiRAH , « Taxonomy of Digital Research Activities in the Humani-tie...
Poster
3D is now commonly used for Cultural Heritage study, valorization and preservation. The gathered experiences make possible to define standard processes and practices to ensure data quality and their preservation. Under the supervision of the French national infrastructure for digital humanities (Huma-Num), the 3D Consortium has thus defined a life...
Article
We propose an automatic framework to recover the illumination of indoor scenes based on a single RGB-D image. Unlike previous works, our method can recover spatially varying illumination without using any lighting capturing devices or HDR information. The recovered illumination can produce realistic rendering results. To model the geometry of the v...
Presentation
3D is becoming a recognized tool for research in Cultural Heritage. In this presentation, based on the work of the MANAO team-project, of the Archeovision research laboratory and of the 3D Consortium for Human and Social Sciences, we will try to demonstrate potential joint researches on acquisition, analyse, visualization and archiving.
Poster
Les Rencontres de la TGIR Huma-Num, Jun 2018, Valpré, France. Le Consortium 3D labellisé en 2014 par Huma-Num regroupe dix unités de recherche travaillant dans le domaine de l’archéologie et du patrimoine, produisant des données 3D et développant des outils pour l’acquisition, la visualisation, l’interprétation et la conservation des données en SHS...
Conference Paper
Full-text available
Plenoptic cameras provide single-shot 3D imaging capabilities, based on the acquisition of the Light-Field, which corresponds to a spatial and directional sampling of all the rays of a scene reaching a detector. Specific algorithms applied on raw Light-Field data allow for the reconstruction of an object at different depths of the scene. Two differ...
Poster
Dariah annual Event 23- 24 mai 2018. The 3D Consortium, accredited in 2014 by Huma-Num, brings together eleven partners working in the field of archaeology and cultural heritage and who already have experience of using 3D technologies and producing 3D models in the scientific context of Humanities and Social Sciences. From 2014 to 2017, the 3D Cons...
Chapter
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...
Chapter
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...
Conference Paper
Spherical multitouch displays offer exciting possibilities but are still costly. In this paper, we describe hardware and software considerations to build a more affordable one, with off-the-shelf optical components and 3D printed elements. We exploit the technology of laser-beam steering projectors and use optical tracking for multitouch.
Conference Paper
We introduce a new approach for snapshot imaging of time-resolved, non-stationary 3D fluid flows. Based on Particle Imaging Velocimetry (PIV), a well-established technique for fluid flow analysis, we propose a novel approach for spectral encoding of the third dimension. To do so, we illuminate the flow volume with a stack of monochromatic light pla...
Conference Paper
Common spatial augmented reality techniques use video projection to superimpose virtual information over a physical scene. As the augmentation happens directly in the real world, multiple users can see the augmented scene, however, the augmentation is the same for all users. We introduce EgoSAR, a new approach that makes it possible to have a perso...
Conference Paper
Monte-Carlo integration techniques for global illumination are popular on GPUs thanks to their massive parallel architecture, but efficient implementation remains challenging. The use of randomly decorrelated low-discrepancy sequences in the path-tracing algorithm allows faster visual convergence. However, the parallel tracing of incoherent rays of...
Conference Paper
Shading techniques are useful to deliver a better understanding of object shapes. When transparent objects are involved, depicting the shape characteristics of each surface is even more relevant. In this paper, we propose a method for rendering transparent scenes or objects using classical tools for shape depiction in real time. Our method provides...
Presentation
Currently, a large trend is the co-designed of hybrid systems that combined optical and digital components. Such systems may help to reach a real convergence of real and virtual worlds (a perfect augmented reality of augmented virtuality). We will illustrate this concept by some of the recent work done inside the MANAO team-project.
Conference Paper
We present a method to synthesize procedural models with global structures, such as growth plants, on existing surfaces at interactive time. More generally, our approach extends shape grammars to enable context-sensitive procedural generation on the GPU. Central to our framework is the unified representation of external contexts as texture maps. Th...
Article
Moving least squares (MLS) surface approximation is a popular tool for the processing and reconstruction of non-structured and noisy point clouds. This paper introduces a new variant improving the approximation quality when the underlying surface is assumed to be locally developable, which is often the case in point clouds coming from the acquisiti...
Article
Full-text available
The possibility to use real world light sources (aka luminaires) for synthesizing images greatly contributes to their physical realism. Among existing models, the ones based on light fields are attractive due to their ability to represent faithfully the near-field and due to their possibility of being directly acquired. In this paper, we introduce...
Conference Paper
Full-text available
Procedural representations are powerful tools to generate highly detailed objects through amplification rules. However controlling such rules within environment contexts (e.g., growth on shapes) is restricted to CPU-based methods, leading to limited performances. To interactively control shape grammars, we introduce a novel approach based on a marc...
Article
Full-text available
Cultural heritage artifacts often contain details that are difficult to distinguish due to aging effects such as erosion. We propose the revealing flashlight, a new interaction and visualization technique in spatial augmented reality that helps to reveal the detail of such artifacts. We locally and interactively augment a physical artifact by proje...
Article
This paper introduces a system for the direct editing of highlights produced by anisotropic BRDFs, which we call anisotropic highlights. We first provide a comprehensive analysis of the link between the direction of anisotropy and the shape of highlight curves for arbitrary object surfaces. The gained insights provide the required ingredients to in...
Conference Paper
Background Many students in Computer Science do not have a sufficient background in applied mathematics to employ state-of-the-art optimization techniques and to judge the outcome of such techniques critically (e.g. regarding the stability/quality/accuracy of their output). At the same time, the use of optimization techniques in computer graphics i...
Technical Report
This deliverable represents the first iteration of an on-going set of activities aimed at identifying the best practices of virtual museums regarding portability, usability and integration. This defines a scaffold of criteria useful for the evaluation of portability (intended as multi­-fruition modes), tangible visualisation and interaction techniq...
Article
We introduce a new approach for defining continuous non-oriented gradient fields from discrete inputs, a fundamental stage for a variety of computer graphics applications such as surface or curve reconstruction, and image stylization. Our approach builds on a moving least square formalism that computes higher-order local approximations of non-orien...
Conference Paper
Full-text available
La Réalité Augmentée Spatiale (RAS) permet d'enrichir des objets du monde réel par apposition d'informations numériques à l'aide de vidéo-projecteurs. Elle présente un fort potentiel pour introduire de nouvelles techniques d'interaction, car la co-localisation de l'espace de rendu et de l'espace d'interaction dans le monde réel permet de se baser s...
Poster
Full-text available
here are two goals for the project. The first one (a vision goal) is to extract material characteristics from a single image of a sphere. The second one (a computer graphics one) is to transfer its appearance to another shape and manipulate material & lighting.
Poster
Full-text available
This poster introduces a system for the direct editing of highlights produced by anisotropic BRDFs, which we call anisotropic highlights. We first provide a comprehensive analysis of the link between the direction of anisotropy and the shape of highlight curves for arbitrary object surfaces. The gained insights provide the required ingredients to i...
Article
Monte Carlo Techniques are widely used in Computer Graphics to generate realistic images. Multiple Importance Sampling reduces the impact of choosing a dedicated strategy by balancing the number of samples between different strategies. However, an automatic choice of the optimal balancing remains a difficult problem. Without any scene characteristi...
Poster
The visual and material properties of cultural heritage artifacts provide important information about their history. For example, traces of wear and tear inform us about an object's use. However, changes caused by manual handling or corrosion might also result in loss of either geometric properties, such as the deterioration of fine inscriptions, o...
Conference Paper
Full-text available
We introduce a simple and effective technique for light-based importance sampling of dynamic environment maps based on the formalism of Multiple Importance Sampling (MIS). The core idea is to balance per pixel the number of samples selected on each cube map face according to a quick and conservative evaluation of the lighting contribution: this inc...
Article
Full-text available
Over the last two decades, much effort has been devoted to accurately measure Bidirectional Reflectance Distribution Functions (BRDFs) of real-world materials and to efficiently use the resulting data during the rendering process. Because of their size, it is difficult to directly use measured BRDFs for real-time applications, and fitting the most...
Article
Full-text available
We present a novel method for producing convincing pictures of shaded objects based entirely on 2D image operations. This approach, which we call image-based shading design, offers direct artistic control in the picture plane by deforming image primitives so that they appear to conform to specific 3D shapes. Using a differential analysis of reflect...
Presentation
In this presentation, we introduce the work on Augmented Reality in the MANAO research group. We focus on our Focus and Context Rendering approach for Augmented Reality. We demonstrate that the use of expressive stylization of videos and 3D expressive rendering techniques, once combined, ensures that cues from real videos and virtual 3D objects are...
Article
In this paper, we present an analysis technique that leverages the complexity found in detailed 3D models for illustrative shading purposes. Given a smooth base surface with relief, it locates relief features (concavities, convexities and inflections) around each surface point and at multiple scales, using cubic-polynomial fitting. This object-spac...
Article
Full-text available
In augmented reality, one of key tasks to achieve a convincing visual appearance consistency between virtual objects and video scenes is to have a coherent illumination along the whole sequence. As outdoor illumination is largely dependent on the weather, the lighting condition may change from frame to frame. In this paper, we propose a full image-...
Conference Paper
We present the new Radiance Scaling plugin for Meshlab. This rendering technique allows to depict shape through shading via the modification of light intensities around specific features. The major idea is to correlate the shading with surface feature variations in order to enhance shape details like concavities and convexities. The Radiance Scalin...
Technical Report
This document provides an in-depth analysis of visualization and interaction tools employed in the context of Virtual Museum. This analysis is required to identify and design the tools and the different components that will be part of the Common Implementation Framework (CIF). The CIF will be the base of the web-based services and tools to support...
Article
In this paper, we propose a novel method for normal texture editing based on shading maps. The presented method can be applied on both photo-realistic rendering and non-photorealistic rendering (NPR). By introducing shading interval constraints, the normal texture editing problem is characterized by a quadratic programming approach, which can be ac...
Article
了适于真实及非真实感图形绘制,提出一种基于绘制着色图的法向纹理编辑方法.通过引入着色区间约束概念,设计了一个法向纹理到着色图的非线性二次规划问题模型,并利用GPU技术实现了算法加速,方便了用户交互操作.实验结果表明,对于1024×1024大小的法向纹理,迭代计算的平均时间为3.6ms,能够达到实时的交互.