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VIRTUS - 2025

2025​​​‌Activity reportProject-TeamVIRTUS​

RNSR: 202224309G
  • Research center​‌ Inria Centre at Rennes​​ University
  • In partnership with:​​​‌Université Rennes 2, Université​ de Rennes
  • Team name:​‌ The VIrtual Us
  • In​​ collaboration with:Institut de​​​‌ recherche en informatique et​ systèmes aléatoires (IRISA), Mouvement,​‌ Sport, Santé (M2S)

Creation​​ of the Project-Team: 2022​​​‌ July 01

Each year,​ Inria research teams publish​‌ an Activity Report presenting​​ their work and results​​​‌ over the reporting period.​ These reports follow a​‌ common structure, with some​​ optional sections depending on​​​‌ the specific team. They​ typically begin by outlining​‌ the overall objectives and​​ research programme, including the​​​‌ main research themes, goals,​ and methodological approaches. They​‌ also describe the application​​ domains targeted by the​​​‌ team, highlighting the scientific​ or societal contexts in​‌ which their work is​​ situated.

The reports then​​​‌ present the highlights of​ the year, covering major​‌ scientific achievements, software developments,​​ or teaching contributions. When​​​‌ relevant, they include sections​ on software, platforms, and​‌ open data, detailing the​​ tools developed and how​​​‌ they are shared. A​ substantial part is dedicated​‌ to new results, where​​ scientific contributions are described​​​‌ in detail, often with​ subsections specifying participants and​‌ associated keywords.

Finally, the​​ Activity Report addresses funding,​​​‌ contracts, partnerships, and collaborations​ at various levels, from​‌ industrial agreements to international​​ cooperations. It also covers​​​‌ dissemination and teaching activities,​ such as participation in​‌ scientific events, outreach, and​​ supervision. The document concludes​​​‌ with a presentation of​ scientific production, including major​‌ publications and those produced​​ during the year.

Keywords​​​‌

Computer Science and Digital​ Science

  • A5.5.4. Animation
  • A5.6.1.​‌ Virtual reality
  • A5.6.3. Avatar​​ simulation and embodiment
  • A5.11.1.​​​‌ Human activity analysis and​ recognition
  • A9.3. Signal processing​‌

Other Research Topics and​​ Application Domains

  • B1.2. Neuroscience​​​‌ and cognitive science
  • B2.8.​ Sports, performance, motor skills​‌
  • B7.1.1. Pedestrian traffic and​​ crowds
  • B9.3. Medias
  • B9.5.6.​​​‌ Data science

1 Team​ members, visitors, external collaborators​‌

Research Scientists

  • Julien Pettre​​ [Team leader,​​​‌ INRIA, Senior Researcher​, HDR]
  • Samuel​‌ Boivin [INRIA,​​ Researcher]
  • Stéphane Donikian​​​‌ [INRIA, Senior​ Researcher, from Apr​‌ 2025, HDR]​​
  • Ludovic Hoyet [INRIA​​​‌, Researcher, HDR​]
  • Katja Zibrek [​‌INRIA, ISFP]​​

Faculty Members

  • Kadi Bouatouch​​​‌ [UNIV RENNES,​ HDR]
  • Mathieu Chambe​‌ [UNIV RENNES,​​ from Sep 2025]​​
  • Marc Christie [UNIV​​​‌ RENNES, Associate Professor‌]
  • Anne Helene Olivier‌​‌ [UNIV RENNES II​​, Associate Professor,​​​‌ HDR]

Post-Doctoral Fellows‌

  • Agathe Bilhaut [UNIV‌​‌ RENNES II, Post-Doctoral​​ Fellow, from Apr​​​‌ 2025 until Aug 2025‌]
  • Ahmed Syed [‌​‌INRIA, Post-Doctoral Fellow​​]
  • Pierre Vauclin [​​​‌UNIV RENNES II,‌ Post-Doctoral Fellow, from‌​‌ Sep 2025]
  • Lezhong​​ Wang [UNIV RENNES​​​‌, Post-Doctoral Fellow,‌ from Dec 2025]‌​‌

PhD Students

  • Kelian Baert​​ [TECHNICOLOR, CIFRE​​​‌]
  • Thomas Bouyer [‌CEA, CIFRE]‌​‌
  • Philippe De Clermont Gallerande​​ [INTERDIGITAL, CIFRE​​​‌]
  • Celine Finet [‌INRIA]
  • Théo Gerard‌​‌ [UNIV RENNES]​​
  • Bhaswar Gupta [UNIV​​​‌ RENNES, from Dec‌ 2025]
  • Alexis Holzbacher-Jensen‌​‌ [INRIA, from​​ Nov 2025]
  • Alexis​​​‌ Holzbacher-Jensen [UNIV RENNES‌, until Oct 2025‌​‌]
  • Kilian Marcelin [​​INRIA, from Nov​​​‌ 2025]
  • Jordan Martin‌ [LCPP]
  • Xiaoyuan‌​‌ Wang [ENS RENNES​​]
  • Tony Wolff [​​​‌UNIV RENNES]
  • Kebing‌ Xue [INRIA,‌​‌ from Oct 2025]​​

Technical Staff

  • François Bourel​​​‌ [UNIV RENNES]‌
  • Bhaswar Gupta [INRIA‌​‌, Engineer, until​​ Oct 2025]
  • Anthony​​​‌ Mirabile [UNIV RENNES‌ , from Sep 2025‌​‌]
  • Alice Phung-Ngoc [​​UNIV RENNES, Engineer​​​‌, from May 2025‌]

Interns and Apprentices‌​‌

  • Iwan Derouet [INRIA​​, Intern, from​​​‌ Jun 2025 until Aug‌ 2025]
  • Theo Hourmand‌​‌ [ENS RENNES,​​ Intern, from Oct​​​‌ 2025]
  • Raphaël Manus‌ [Ecole Polytechnique]‌​‌
  • Raphael Manus [Université​​ de Rennes ]
  • Clara​​​‌ Moy [ENS RENNES‌, Intern, until‌​‌ May 2025]
  • Alexis​​ Pechard [UNIV RENNES​​​‌ II, Intern,‌ from Dec 2025]‌​‌
  • Mehmet Akif Sahin [​​INRIA, Intern,​​​‌ from Jun 2025 until‌ Aug 2025]
  • Alexandre‌​‌ Watrin [INRIA,​​ Intern, from Mar​​​‌ 2025 until Aug 2025‌]

Administrative Assistant

  • Gwenaelle‌​‌ Lannec [UNIV RENNES​​]

Visiting Scientists

  • Krista​​​‌ Best [Université Laval,‌ CIRRIS, from Sep‌​‌ 2025 until Oct 2025​​]
  • Arnau Colom Pasqual​​​‌ De Riquelme [UNIV‌ POMPEU FABRA, from‌​‌ Apr 2025 until Jun​​ 2025]
  • Jean-Bernard Hayet​​​‌ [CIMAT, Mexico,‌ from Dec 2025]‌​‌
  • Vinu Kamalasanan [TU​​ Clausthal, Allemagne, from​​​‌ Sep 2025 until Sep‌ 2025]
  • Francisco Ortega‌​‌ [Colorado State University​​, from Jul 2025​​​‌ until Jul 2025]‌
  • Angelo Silvino [Université‌​‌ de Campania Luigi Vanvitelli​​, from Sep 2025​​​‌]

External Collaborator

  • Aline‌ Hufschmitt [UNIV RENNES‌​‌]

2 Overall objectives​​

The VirtUs research team​​​‌ focuses on developing tools‌ for building and studying‌​‌ the usage of immersive​​ simulations of populated spaces.​​​‌

2.1 Context

Virtual reality‌ has made significant breakthroughs‌​‌ in several specific domains​​ that are central to​​​‌ our research interests. First,‌ in the professional sphere,‌​‌ particularly within the creative​​ industry, virtual reality has​​​‌ joined the palette of‌ tools used in the‌​‌ production of works, especially​​​‌ complex productions such as​ films. In other domains,​‌ virtual reality serves as​​ a communication tool. While​​​‌ this also extends to​ the industrial sector, these​‌ applications are highly developed​​ in the private sphere,​​​‌ where virtual reality has​ been recognized as a​‌ potential medium for distant​​ social relations that are​​​‌ enhanced compared to existing​ communication means. Finally, virtual​‌ reality is being exploited​​ in our own field,​​​‌ scientific research, where it​ has proven to be​‌ a powerful research tool​​ that complements the experimental​​​‌ apparatus used by researchers​ to explore human behavior​‌ when exposed to certain​​ situations, here recreated through​​​‌ the medium of virtual​ reality.

2.2 Research Vision​‌

VirtUs was born from​​ the observation that, across​​​‌ all these applications, a​ salient research challenge concerns​‌ populated immersive universes. This​​ represents a particularly difficult​​​‌ aspect in the development​ of tools, a difficulty​‌ that arises specifically from​​ the need to represent​​​‌ and animate humans in​ the scene. This challenge​‌ stems from the complexity​​ and variety of human​​​‌ behaviors, as well as​ from users' sensitivity to​‌ the quality of these​​ representations. VirtUs emerged from​​​‌ the desire to provide​ technical solutions to these​‌ needs, but also to​​ test them against specific​​​‌ use cases, including the​ domains mentioned above.

The​‌ necessary qualities of immersive​​ content and the technical​​​‌ means to create them​ are intimately linked to​‌ the domains in which​​ they are applied. The​​​‌ required level of visual​ realism, the flexibility needed​‌ for content creation, and​​ the expressiveness of content​​​‌ for communicating certain information​ differ radically from one​‌ type of application to​​ another. A strategic positioning​​​‌ of VirtUs is to​ be scientifically engaged on​‌ both these facets: the​​ creation of tools for​​​‌ immersive simulation and the​ exploration of applications of​‌ our simulators, with a​​ central focus on the​​​‌ human agents that populate​ our scenes.

This dual​‌ commitment allows us to​​ advance both the technical​​​‌ foundations and the practical​ understanding of populated virtual​‌ environments. On one hand,​​ we develop novel computational​​​‌ approaches for representing and​ animating virtual humans with​‌ varying degrees of fidelity​​ and behavioral sophistication, addressing​​​‌ challenges in real-time rendering,​ crowd simulation, and procedural​‌ animation. On the other​​ hand, we engage with​​​‌ concrete application domains to​ understand how different requirements—whether​‌ it be the photorealistic​​ rendering needed for creative​​​‌ industries, the communicative clarity​ required for social VR​‌ platforms, or the experimental​​ control necessary for scientific​​​‌ research—shape the design and​ implementation of our simulation​‌ tools.

The VirtUs team's​​ approach is fundamentally interdisciplinary,​​​‌ bringing together expertise in​ computer graphics, artificial intelligence,​‌ human-computer interaction, and cognitive​​ science, complemented by collaborations​​​‌ with domain experts from​ creative industries, social sciences,​‌ and applied research fields.​​ By maintaining this bidirectional​​​‌ engagement between technical innovation​ and application-driven research, we​‌ aim to create immersive​​ simulation tools that are​​​‌ both scientifically rigorous and​ practically relevant, advancing our​‌ understanding of how populated​​ virtual environments can serve​​​‌ diverse professional, creative, and​ scientific purposes.

3 Research​‌ program

In concrete terms,​​ our overall objective translates​​ into scientific objectives for​​​‌ the VirtUs team across‌ the following themes:

Modeling‌​‌ and Animation of Virtual​​ Humans.

This theme encompasses​​​‌ the performance of animation‌ techniques for virtual reality‌​‌ applications, the physical and​​ perceptual realism of animations,​​​‌ real-time interaction capabilities, and‌ the controllability of behaviors‌​‌ to develop scenarios. Our​​ research addresses the fundamental​​​‌ challenge of creating virtual‌ humans that are not‌​‌ only visually convincing but​​ also behaviorally responsive and​​​‌ adaptable to diverse interactive‌ contexts.

Massive Scene Population‌​‌ Techniques.

This work focuses​​ on scaling to large​​​‌ environments, crowd modeling and‌ simulation, and the authoring‌​‌ of populated scenes. We​​ investigate methods that enable​​​‌ the creation of densely‌ populated virtual spaces while‌​‌ maintaining computational efficiency and​​ behavioral plausibility, from procedural​​​‌ generation techniques to intelligent‌ distribution algorithms that respect‌​‌ spatial and social constraints.​​

Augmented Scene Capture and​​​‌ Composition Techniques.

This theme‌ includes scene capture, performance‌​‌ capture, tracking, and scene​​ representation and rendering. Our​​​‌ research explores how to‌ bridge the gap between‌​‌ real-world observations and virtual​​ reconstructions, developing pipelines that​​​‌ can efficiently capture, process,‌ and integrate real human‌​‌ performances and environments into​​ immersive simulations, enabling hybrid​​​‌ approaches that combine captured‌ and synthetic content.

4‌​‌ Application domains

Application Domains​​

VirtUs targets three major​​​‌ application domains:

4.1 Design‌ and Management of Public‌​‌ Spaces

Context: Working with​​ railway stations (SNCF) and​​​‌ mass events (Paleo, Hellfest)‌

Applications:

  • Evaluation of public‌​‌ space design before construction​​
  • Flow prediction and venue​​​‌ layout optimization
  • Crowd safety‌ and comfort assessment
  • Emergency‌​‌ evacuation planning
  • Dense crowd​​ behavior analysis
  • Festival and​​​‌ event management

Objective: Enable‌ managers to immerse themselves‌​‌ in virtual replicas of​​ spaces to assess design​​​‌ quality and collect behavioral‌ data from immersed participants.‌​‌

4.2 Social Virtual Reality​​ and Wellbeing

Context: Communication​​​‌ and interaction in populated‌ virtual worlds

Applications:

  • Avatar-mediated‌​‌ communication
  • Interactive virtual agents​​ for psychotherapy
  • Study of​​​‌ embodiment and presence
  • Ethical‌ considerations in the Metaverse‌​‌
  • Detection and prevention of​​ inappropriate behavior
  • Mental health​​​‌ and wellbeing in VR‌

Objective: Create realistic expressive‌​‌ virtual agents capable of​​ natural interaction while addressing​​​‌ ethical issues and promoting‌ user wellbeing.

4.3 Creative‌​‌ Industries (Cinema and Visual​​ Effects)

Context: Film production,​​​‌ animation, and visual content‌ creation

Applications:

  • Virtual reality‌​‌ as a design tool​​ for filmmakers
  • Pre-visualization of​​​‌ complex scenes
  • Character animation‌ workflows
  • Seamless integration of‌​‌ virtual objects into real​​ footage
  • Cinematographic style transfer​​​‌
  • Volumetric content authoring
  • Camera‌ control and virtual cinematography‌​‌

Objective: Support the creative​​ process by providing immersive​​​‌ tools for scene design,‌ shot composition, and content‌​‌ manipulation, leveraging VR to​​ enhance filming and post-production​​​‌ workflows.

Unifying Paradigm: Across‌ all domains, VirtUs leverages‌​‌ Extended Reality (XR) both​​ as a support for​​​‌ technological innovation (enabling designers‌ to experiment with creations)‌​‌ and as a scientific​​ research tool (exposing users​​​‌ to controlled, repeatable situations‌ for behavioral observation).

5‌​‌ Social and environmental responsibility​​

The VirtUs team is​​​‌ tackling the environmental issue‌ by reshaping its ecosystem,‌​‌ in particular by redeveloping​​ its national network, and​​​‌ is putting its scientific‌ objectives and methodological approach‌​‌ at the service of​​​‌ applications linked to low-carbon​ energy mobility.

5.1 Footprint​‌ of research activities

VirtUs​​ is seeking to reduce​​​‌ its footprint by 'relocating'​ its research activities and​‌ redeploying its local network​​ within France. In particular,​​​‌ the team has submitted​ several collaborative research projects​‌ at national level with​​ joint partners, including the​​​‌ SNCF (the national rail​ transport company), the "Museum​‌ National d'Histoire Naturelle", as​​ well as the Gustave​​​‌ Eiffel University.

Some members​ of the VirtUs team,​‌ and in particular Ludovic​​ Hoyet, CRCN Inria, are​​​‌ actively taking part in​ discussion groups on reducing​‌ the carbon footprint generated​​ by research activities. For​​​‌ example, he is one​ of the two "Environmental​‌ Impact Reduction and Awareness​​ Chairs" for the IEEE​​​‌ VR 2025 conference.

5.2​ Impact of research results​‌

VirtUs is also revisiting​​ the applications of its​​​‌ research, seeking to address​ issues related to mobility​‌ and low-carbon modes of​​ travel. Working with the​​​‌ SNCF, the VirtUs team​ is looking to tackle​‌ issues of crowd management​​ in transport infrastructures. With​​​‌ teams from the University​ of Gustave Eiffel, VirtUs​‌ is exploring issues relating​​ to the development of​​​‌ multi-modal traffic zones, and​ in particular pedestrian-bicycle interactions.​‌ Finally, with the "Muséum​​ National d'Histoire Naturelle", VirtUs​​​‌ is exploring applications to​ Marine Biology, to better​‌ understand the impact of​​ human activities on marine​​​‌ wildlife.

6 Highlights of​ the year

6.1 Strong​‌ involvement of the team​​ in organizing the IEEE​​​‌ VR 2025 conference

Participants:​ Julien Pettré [contact],​‌ Anne-Hélène Olivier, Ludovic​​ Hoyet, Katja Zibrek​​​‌.

Several members of​ the VirtUs team were​‌ heavily involved in organizing​​ the IEEE VR conference.​​​‌ In particular, Anne-Hélène Olivier​ served as co-general chair​‌ for the conference. Katja​​ Zibrek was XR Gallery​​​‌ co-chair (a new chapter​ for this conference introduced​‌ in 2025). Ludovic Hoyet​​ was Environmental Impact Reduction​​​‌ and Awareness co-chair. Gwenaelle​ Lannec was Local Arrangement​‌ co-chair. Julien Pettré was​​ Social Events chair. Several​​​‌ students or engineers in​ the team also took​‌ part to the organisation​​ team, including Céline Finet​​​‌ and Rémi Cambuzat.

6.2​ Team evaluation

In its​‌ fourth year of existence,​​ the team was evaluated​​​‌ during the September 2025​ wave. The evaluation is​‌ still being finalized, but​​ the experts' reports highlighted​​​‌ the very high quality​ of VirtUs' scientific contributions​‌ during its first period​​ (July 1, 2022 -​​​‌ August 31, 2025).

7​ Latest software developments, platforms,​‌ open data

7.1 Latest​​ software developments

7.1.1 AvatarReady​​​‌

  • Name:
    A unified platform​ for the next generation​‌ of our virtual selves​​ in digital worlds
  • Keywords:​​​‌
    Avatars, Virtual reality, Augmented​ reality, Motion capture, 3D​‌ animation, Embodiment
  • Scientific Description:​​
    AvatarReady is an open-source​​​‌ tool (AGPL) written in​ C#, providing a plugin​‌ for the Unity 3D​​ software to facilitate the​​​‌ use of humanoid avatars​ for mixed reality applications.​‌ Due to the current​​ complexity of semi-automatically configuring​​​‌ avatars coming from different​ origins, and using different​‌ interaction techniques and devices,​​ AvatarReady aggregates several industrial​​​‌ solutions and results from​ the academic state of​‌ the art to propose​​ a simple and fast​​ way to use humanoid​​​‌ avatars in mixed reality‌ in a seamless way.‌​‌ For example, it is​​ possible to automatically configure​​​‌ avatars from different libraries‌ (e.g., rocketbox, character creator,‌​‌ mixamo), as well as​​ to easily use different​​​‌ avatar control methods (e.g.,‌ motion capture, inverse kinematics).‌​‌ AvatarReady is also organized​​ in a modular way​​​‌ so that scientific advances‌ can be progressively integrated‌​‌ into the framework. AvatarReady​​ is furthermore accompanied by​​​‌ a utility to generate‌ ready-to-use avatar packages that‌​‌ can be used on​​ the fly, as well​​​‌ as a website to‌ display them and offer‌​‌ them for download to​​ users.
  • Functional Description:
    AvatarReady​​​‌ is a Unity tool‌ to facilitate the configuration‌​‌ and use of humanoid​​ avatars for mixed reality​​​‌ applications. It comes with‌ a utility to generate‌​‌ ready-to-use avatar packages and​​ a website to display​​​‌ them and offer them‌ for download.
  • URL:
  • Contact:
    Ludovic Hoyet

7.1.2​​ PyNimation

  • Keywords:
    Moving bodies,​​​‌ 3D animation, Synthetic human‌
  • Scientific Description:
    PyNimation is‌​‌ a python-based open-source (AGPL)​​ software for editing motion​​​‌ capture data which was‌ initiated because of a‌​‌ lack of open-source software​​ enabling to process different​​​‌ types of motion capture‌ data in a unified‌​‌ way, which typically forces​​ animation pipelines to rely​​​‌ on several commercial software.‌ For instance, motions are‌​‌ captured with a software,​​ retargeted using another one,​​​‌ then edited using a‌ third one, etc. The‌​‌ goal of Pynimation is​​ therefore to bridge the​​​‌ gap in the animation‌ pipeline between motion capture‌​‌ software and final game​​ engines, by handling in​​​‌ a unified way different‌ types of motion capture‌​‌ data, providing standard and​​ novel motion editing solutions,​​​‌ and exporting motion capture‌ data to be compatible‌​‌ with common 3D game​​ engines (e.g., Unity, Unreal).​​​‌ Its goal is also‌ simultaneously to provide support‌​‌ to our research efforts​​ in this area, and​​​‌ it is therefore used,‌ maintained, and extended to‌​‌ progressively include novel motion​​ editing features, as well​​​‌ as to integrate the‌ results of our research‌​‌ projects. At a short​​ term, our goal is​​​‌ to further extend its‌ capabilities and to share‌​‌ it more largely with​​ the animation/research community.
  • Functional​​​‌ Description:

    PyNimation is a‌ framework for editing, visualizing‌​‌ and studying skeletal 3D​​ animations, it was more​​​‌ particularly designed to process‌ motion capture data. It‌​‌ stems from the wish​​ to utilize Python’s data​​​‌ science capabilities and ease‌ of use for human‌​‌ motion research.

    In its​​ version 1.0, Pynimation offers​​​‌ the following functionalities, which‌ aim to evolve with‌​‌ the development of the​​ tool : - Import​​​‌ / Export of FBX,‌ BVH, and MVNX animation‌​‌ file formats - Access​​ and modification of skeletal​​​‌ joint transformations, as well‌ as a certain number‌​‌ of functionalities to manipulate​​ these transformations - Basic​​​‌ features for human motion‌ animation (under development, but‌​‌ including e.g. different methods​​ of inverse kinematics, editing​​​‌ filters, etc.). - Interactive‌ visualisation in OpenGL for‌​‌ animations and objects, including​​ the possibility to animate​​​‌ skinned meshes

  • URL:
  • Contact:
    Ludovic Hoyet

7.2‌​‌ New platforms

7.2.1 Infinadeck​​​‌ omnidirectionnal treadmill

Participants: Anne-Hélène​ Olivier [contact], Julien​‌ Pettré.

Figure 1

A person​​ is using a virtual​​​‌ reality (VR) system on​ an "INFINADECK" platform, wearing​‌ a VR headset and​​ holding a controller. The​​​‌ setup includes a treadmill-like​ device with overhead safety​‌ bars, and a screen​​ and equipment are placed​​​‌ to the side. The​ background displays the "INFINADECK"​‌ logo prominently. The user​​ appears to be walking​​​‌ in place, likely experiencing​ an immersive VR environment.​‌ (Description generated at January​​ 23rd, 2026 by Albert​​​‌ AI with the model​ Mistral-Small-3.2-24B)

Figure 1:​‌ Picture of the Infinadeck​​ platform

The VIRTUS team​​​‌ has recently acquired an​ omnidirectional treadmill, the Infinadeck,​‌ significantly strengthening its experimental​​ infrastructure for immersive virtual​​​‌ environment research. The Infinadeck​ is an active-surface locomotion​‌ platform based on an​​ array of independently actuated​​​‌ conveyor modules arranged along​ two orthogonal axes. This​‌ design enables real-time compensation​​ of the user’s movements,​​​‌ keeping the user centered​ on the platform while​‌ allowing natural walking in​​ all directions, including forward,​​​‌ backward, lateral motions, and​ rotations. The system relies​‌ on high-frequency position and​​ velocity sensing combined with​​​‌ a low-latency real-time control​ loop, ensuring precise, stable,​‌ and responsive behavior. Fully​​ compatible with standard virtual​​​‌ reality systems (HMDs and​ optical or inertial tracking​‌ solutions), the Infinadeck supports​​ realistic walking speeds and​​​‌ substantial user loads, making​ it a state-of-the-art device​‌ for research in VR​​ locomotion, human-environment interaction, and​​​‌ movement behavior analysis.

7.3​ Open data

  • UnderPressure

     

    Web​‌ site: https://­doi.­org/­10.­57745/­FYXKXY

    Self-assessment:

    • Dataset​​ Family: Dataset as a​​​‌ Vehicle for Research.
    • Audience:​ dataset made openly available​‌ to people inside and​​ outside the field
    • Free​​​‌ Description: UnderPressure is a​ unique dataset of human​‌ motion sequences captured together​​ with pressure insoles data,​​​‌ which was captured originally​ for our work on​‌ detecting human foot contacts​​ and estimating ground reaction​​​‌ force for footskate cleanup​ of motion capture data.​‌
  • 4DHumanPercept

     

    Web site: https://­doi.­org/­10.­57745/­NZHDFY​​

    Self-assessment:

    • Dataset Family: Dataset​​​‌ as a Vehicle for​ Research.
    • Audience: dataset made​‌ openly available to people​​ inside and outside the​​​‌ field
    • Free Description: his​ dataset was created for​‌ and used in the​​ work ”Quality assessment of​​​‌ 3D human animation: Subjective​ and objective evaluation”. It​‌ contains virtual human animations​​ acquired using a 4D​​​‌ acquisition system and distorted​ along controlled factors with​‌ corresponding per- ceptual similarity​​ labels  11.
  • Pushing​​​‌

     

    Web site: https://­doi.­org/­10.­5281/­zenodo.­10512651

    Self-assessment:​

    • Dataset Family: Dataset as​‌ a Vehicle for Research.​​
    • Audience: dataset made openly​​​‌ available to people inside​ and outside the field​‌
    • Free Description: This dataset​​ is composed of C3D​​​‌ files corresponding to full​ body motion of participants​‌ undergoing external perturbation at​​ shoulder height with different​​​‌ sensory conditions. The temporal​ force profiles of the​‌ perturbations are also available.​​

8 New results

8.1​​​‌ Classification of first recovery​ steps after quiet standing​‌ following external perturbation from​​ different directions

Participants: Julien​​​‌ Pettré [contact], Anne-Hélène​ Olivier, Ludovic Hoyet​‌.

Figure 2

Overview of the​​ main concepts of the​​​‌ approach

Figure 2:​ Overview of the different​‌ variables of the methods:​​ (a) Instructed angles and​​ the location of the​​​‌ perturbation application. For clarity,‌ the referential of the‌​‌ instructed angles has been​​ redefined in this study​​​‌ compared to Chatagnon et‌ al. (2023). (b) Representation‌​‌ of the perturbation angles.​​ The Instructed angle (gray)​​​‌ is defined as the‌ angle between the initial‌​‌ sagittal plane and the​​ perturbation direction given to​​​‌ the experimenter. The Ground‌ Truth angle (red) is‌​‌ the angle between the​​ sagittal plane and the​​​‌ direction of the participant's‌ CoM velocity at peak‌​‌ perturbation intensity. The Estimated​​ angle (purple) corresponds to​​​‌ the angle between the‌ sagittal plane and the‌​‌ CoM velocity direction at​​ the moment of minimal​​​‌ Ttb before step initiation.‌ (c) Representation of the‌​‌ BoS, depicted as the​​ polygon formed by linking​​​‌ all external foot markers‌ (red). Blue dots indicate‌​‌ the positions of the​​ motion-capture markers. (For interpretation​​​‌ of the references to‌ color in this figure‌​‌ legend, the reader is​​ referred to the web​​​‌ version of this article.)‌

The paper 8 and‌​‌ the poster 22 are​​ related to our studies​​​‌ on physical interactions in‌ dense crowds. It focuses‌​‌ on the recovery of​​ equilibrium after disturbances that​​​‌ can occur during these‌ interactions. Recovery from external‌​‌ perturbations typically involves stepping,​​ with the perturbation direction​​​‌ playing a key role‌ in determining the recovery‌​‌ strategy. To date, classifications​​ of these stepping strategies​​​‌ have relied on prior‌ knowledge of perturbation direction,‌​‌ which is not always​​ available when considering experimental​​​‌ paradigms close to real-world‌ scenario. Here, we introduce‌​‌ a novel Unified classification​​ method that enables the​​​‌ labeling of first recovery‌ steps based solely on‌​‌ body kinematics. We have​​ also developed and validated​​​‌ a logistic regression model‌ that effectively differentiates between‌​‌ different recovery strategies. The​​ key ideas of the​​​‌ classification method is illustrated‌ in Figure 2.‌​‌

8.2 Herds From Video:​​ Learning a Microscopic Herd​​​‌ Model From Macroscopic Motion‌ Data

Participants: Julien Pettré‌​‌ [contact].

Figure 3

Overview of​​ the main concepts of​​​‌ the approach

Figure 3‌: Our method can‌​‌ simulate individual agents to​​ replicate herd behaviour learnt​​​‌ from a video containing‌ many animals. [Left and‌​‌ middle] The original video​​ (lower-right) and our simulation​​​‌ (upper-left), optimized to fit‌ the macroscopic density and‌​‌ velocity fields over a​​ coarse grid. [Right] An​​​‌ authored simulation in which‌ a herd transitions between‌​‌ the two illustrated behaviours,​​ featuring narrow and broad​​​‌ formations.

We present a‌ method for animating animal‌​‌ herds that automatically tunes​​ a microscopic herd model​​​‌ from a short video‌ clip of real animals,‌​‌ building on recent work​​ on learning collective motion​​​‌ from dense visual observations‌ 9. The method‌​‌ targets dense herd scenarios,​​ where individual motions cannot​​​‌ be reliably extracted due‌ to occlusion and limited‌​‌ observability. Our main contribution​​ is a novel framework​​​‌ that infers macroscopic herd‌ behavior from such videos‌​‌ and subsequently derives the​​ microscopic agent parameters that​​​‌ best reproduce this behavior.‌ Some results of the‌​‌ method are illustrated in​​ Figure 3.

To​​​‌ enable this learning process,‌ we extend standard agent-based‌​‌ models by introducing an​​​‌ explicit separation between leaders​ and followers, incorporating realistic​‌ occlusion and field-of-view constraints​​ inspired by animal perception,​​​‌ supporting differentiable parameter optimization,​ and improving authoring control.​‌ We validate our approach​​ by demonstrating that, once​​​‌ optimized, the learned social-force​ and perception parameters are​‌ sufficiently accurate to predict​​ subsequent frames of the​​​‌ video, including macroscopic properties​ not explicitly used during​‌ optimization, in line with​​ and beyond the predictive​​​‌ capabilities reported by Gong​ et al.

Furthermore, the​‌ extracted herding characteristics can​​ be transferred to new​​​‌ terrains using a palette-​ and region-painting approach that​‌ generalizes across different herd​​ sizes and leader trajectories.​​​‌ This enables the authoring​ of herd animations in​‌ novel environments while preserving​​ the learned collective behavior.​​​‌

8.3 Eliminating bias in​ pedestrian density estimation: A​‌ Voronoi cell perspective

Participants:​​ Julien Pettré [contact].​​​‌

Figure 4

Overview of the main​ concepts of the approach​‌

Figure 4: Temporal​​ variations of density as​​​‌ a function of time,​ along the trajectory of​‌ a given pedestrian. Density​​ is determined by (a)​​​‌ the classical grid-based method,​ (b) the XT-method, (c)​‌ the Gaussian kernel method.​​ Time sequences are shown​​​‌ for several values of​ the spatial scale dg​‌ , dx, or h​​ and in (b), of​​​‌ the time window T.​

For pedestrians moving without​‌ spatial constraints, extensive research​​ has been devoted to​​​‌ density estimation methods. In​ the paper 10,​‌ we introduce a new​​ approach based on Voronoi​​​‌ cells that enables density​ estimation for individuals within​‌ small, unbounded pedestrian groups.​​ A comprehensive evaluation of​​​‌ existing methods—including both Lagrangian​ and Eulerian approaches commonly​‌ used in similar contexts—reveals​​ significant limitations. In particular,​​​‌ these methods are often​ ill-defined for realistic density​‌ estimation along an individual​​ pedestrian's trajectory, exhibiting systematic​​​‌ biases and fluctuations that​ depend on parameter choices.​‌

This motivates the need​​ for a parameter-independent method​​​‌ capable of eliminating such​ biases. We therefore propose​‌ a modification of the​​ widely used Voronoi-based density​​​‌ estimator that is applicable​ to pedestrian groups regardless​‌ of their size. The​​ proposed method is instantaneous,​​​‌ requiring only the pedestrians'​ positions at a given​‌ time, and does not​​ rely on tunable parameters.​​​‌ It provides a realistic​ estimate of local density​‌ in an individual's neighborhood​​ and retains a clear​​​‌ physical interpretation for both​ small groups and large​‌ crowds across a wide​​ range of situations. We​​​‌ conclude the paper with​ general remarks on the​‌ interpretation and meaning of​​ density measurements in small​​​‌ pedestrian groups, as illustrated​ in 4.

8.4​‌ Daily and seasonal spatial​​ behaviour of waved whelk​​​‌ Buccinum undatum: implications for​ fishery management and restoration​‌

Participants: Julien Pettré [contact]​​, Anne-Hélène Olivier.​​​‌

Figure 5

Overview of the main​ concepts of the approach​‌

Figure 5: Recorded​​ location of all 2020​​​‌ tagged individuals from October​ 2020 to October 2021​‌ with respect to bathymetry​​ of the Petite baie​​​‌ de Saint-Nicolas. Tags (No.​ 21/24/25) show displacements from​‌ August 2019 to October​​ 2021. The yellow diamonds​​​‌ represent the east and​ west main release points​‌ of the tracked individuals​​ of waved whelks Buccinum​​ undatum during the study​​​‌ period.

In the paper‌ 12, we applied‌​‌ our methods to study​​ spatial behaviours to marine​​​‌ species in collaboration with‌ tehe Museum National d'Histoires‌​‌ Naturelles. Many marine invertebrate​​ fisheries are vulnerable to​​​‌ overexploitation and therefore require‌ effective conservation measures to‌​‌ ensure long-term sustainability. In​​ recent years, landings of​​​‌ the waved whelk Buccinum‌ undatum (Linnaeus, 1758) have‌​‌ declined markedly along the​​ coasts of the St.​​​‌ Lawrence (Canada), with decreases‌ of up to 76%‌​‌ reported in some fishing​​ areas. Local overfishing may​​​‌ be partly explained by‌ the species' oviparous reproductive‌​‌ strategy, which limits larval​​ dispersal and restricts connectivity​​​‌ among populations.

Using a‌ two-year acoustic telemetry study,‌​‌ we tracked 20 individuals​​ to characterize their movement​​​‌ behavior and assess their‌ potential for spatial dispersal‌​‌ (illustrated in Figure 5​​). Tagged whelks exhibited​​​‌ substantial daily movements, with‌ mean speeds ranging from‌​‌ 2 to 16 m​​.h-1​​​‌, and showed no‌ significant differences between day‌​‌ and night activity. Both​​ movement speed and habitat​​​‌ usage potential (HUP) varied‌ seasonally, likely reflecting the‌​‌ reproductive cycle: HUP was​​ significantly greater during the​​​‌ breeding season in May‌ (4570 m²) and June‌​‌ (2779 m²) than during​​ the preceding winter months​​​‌ (1046 m²).

Although some‌ individuals traversed a broad‌​‌ depth range, no seasonal​​ pattern was observed along​​​‌ the bathymetric gradient. Overall,‌ the species' limited habitat‌​‌ usage potential constrains individual​​ dispersal, resulting in weak​​​‌ connectivity between neighboring populations‌ and increasing the vulnerability‌​‌ of Buccinum undatum to​​ local overfishing.

8.5 Learning​​​‌ extremely high density crowds‌ as active matters

Participants:‌​‌ Julien Pettré [contact].​​

Figure 6

Overview of the main​​​‌ concepts of the approach‌

Figure 6: Overview.‌​‌ From left to right:​​ optical flow estimation, velocity​​​‌ field generation, initial particle‌ sampling, crowd simulation and‌​‌ loss calculation.

Video-based analysis​​ and prediction of high-density​​​‌ crowds has long been‌ a challenging problem in‌​‌ computer vision. Progress has​​ been hindered by the​​​‌ scarcity of high-quality data‌ and the intrinsic complexity‌​‌ of dense crowd dynamics,​​ where severe occlusions and​​​‌ visual ambiguity make individual‌ tracking or head counting‌​‌ unreliable. As a result,​​ this regime remains relatively​​​‌ under-explored.

In the paper‌ we published in CVPR‌​‌ 2025 15, we​​ introduce a novel approach​​​‌ designed to learn directly‌ from in-the-wild videos, including‌​‌ low-quality footage where standard​​ individual-based methods fail. Our​​​‌ key contribution is the‌ introduction of a physics-based‌​‌ prior for crowd dynamics.​​ We model high-density crowds​​​‌ as active matter: a‌ continuum of active particles‌​‌ subject to stochastic forces,​​ which we term crowd​​​‌ material. This formulation captures‌ collective dynamics beyond individual-level‌​‌ representations.

We combine this​​ physics model with neural​​​‌ networks, resulting in a‌ neural stochastic differential equation‌​‌ framework capable of reproducing​​ complex crowd behaviors. We​​​‌ illustrate our method in‌ Figure 6 Owing to‌​‌ the lack of closely​​ related work, we adapt​​​‌ several existing methods for‌ comparison. Extensive evaluations demonstrate‌​‌ that our approach consistently​​ outperforms state-of-the-art methods in​​​‌ both analysis and forecasting‌ of extremely high-density crowds.‌​‌

Importantly, our model operates​​​‌ in continuous time and​ is grounded in physical​‌ principles, enabling both simulation​​ and interpretability. This stands​​​‌ in contrast to most​ existing deep learning approaches,​‌ which rely on discrete-time​​ formulations and largely function​​​‌ as black boxes.

8.6​ Evaluation of Body Parts​‌ Representations in Motion Reconstruction​​

Participants: Philippe De Clermont​​​‌ Gallerande, Ludovic Hoyet​ [contact].

Figure 7

The different​‌ body decompositions evaluated in​​ our work.

Figure 7​​​‌: The different body​ decompositions evaluated in our​‌ work 14. A​​ Body Parts (BPs) model​​​‌ is a wrapper of​ one, or several, neural​‌ networks reconstructing a body​​ part motion. They are​​​‌ linked together by overlapping​ joints: the BPs Connectors​‌ (orange circles). From left​​ to right: BPs1 (whole-body),​​​‌ BPs2 (upper/lower body), BPs3​ (spine, arms and legs)​‌ and BPs5 (spine, right/left​​ arm, right/left leg).

Acquiring,​​​‌ encoding, transmitting, decoding, and​ displaying motion signals is​‌ an essential challenge in​​ our new world of​​​‌ interconnected immersive applications (XR,​ online games etc.). In​‌ addition to being potentially​​ disturbed by multiple factors​​​‌ (e.g., signal noise, latency,​ packet loss), this motion​‌ data should be modifiable​​ and customizable to fit​​​‌ the needs of specific​ applications. Simultaneously, several approaches​‌ have successfully proposed to​​ explicitly integrate the semantics​​​‌ of the human body​ in a deep learning​‌ framework by separating it​​ into smaller parts. In​​​‌ this work 14,​ we propose to use​‌ such an approach to​​ obtain a robust streamed​​​‌ animation data. Specifically, we​ create and train several​‌ neural networks on the​​ motion of different body​​​‌ parts independently from each​ other (Figure 7).​‌ We further compare the​​ performances of several body​​​‌ decompositions using multiple objective​ reconstruction metrics. Eventually, we​‌ show that this Body​​ Parts approach brings new​​​‌ opportunities compared to a​ compact one, such as​‌ a perfectly partitioned and​​ more interpretable motion data,​​​‌ while obtaining comparable reconstruction​ results.

8.7 How do​‌ people perceive changes in​​ physical bounce model for​​​‌ virtual racket interactions?

Participants:​ Ludovic Hoyet [contact].​‌

Figure 8

The experimental VR Setup​​ used in 17.​​​‌

Figure 8: The​ experimental VR Setup used​‌ in 17. Left:​​ picture of a participant​​​‌ performing the “Perception-Action” block.​ Right: generic virtual room​‌ displayed in the head​​ mounted display.

Nowadays, Virtual​​​‌ Reality is widely used​ in sports, to enhance​‌ physical fitness, or improve​​ specific subskills, such as​​​‌ anticipation skills. However, many​ factors in VR can​‌ alter the experience and​​ make it difficult to​​​‌ transfer the skills trained​ in VR to real​‌ practice. One of these​​ factors is the physical​​​‌ simulation of the virtual​ environment, that may produce​‌ unexpected behaviours. Hence, if​​ users are athletes in​​​‌ ball-based sports, the VR​ training simulator should compute​‌ ball trajectories that look​​ plausible for them. In​​​‌ this work 17,​ our aim is to​‌ evaluate how human perception​​ can be influenced by​​​‌ variations in a ball​ physics’ model. We explore​‌ properties of human perception,​​ the acceptance threshold beyond​​​‌ which a deviation from​ the reference ball trajectory​‌ is perceived more than​​ 50% of time, and​​ the Just-Noticeable Difference (JND)​​​‌ as an indicator of‌ perceptual sensitivity. To this‌​‌ end, we conducted psychophysical​​ experiments where participants were​​​‌ asked to either only‌ observe, or observe and‌​‌ hit virtual bouncing balls​​ simulated with varying coefficients​​​‌ of restitution (COR). We‌ report the acceptance threshold‌​‌ and JND in different​​ conditions. We found that​​​‌ participants detected variations in‌ COR more easily when‌​‌ having the motor task.​​ Additionally, their sensitivity to​​​‌ variations was globally higher‌ when they first performed‌​‌ the perceptual task alone,​​ before the motor task​​​‌ was introduced. These results‌ contribute to the design‌​‌ of credible VR environments​​ involving bouncing objects, such​​​‌ as for virtual sports.‌

8.8 Quality assessment of‌​‌ 3D human animation: Subjective​​ and objective evaluation

Participants:​​​‌ Ludovic Hoyet, Anne-Hélène‌ Olivier [contact], Katja‌​‌ Zibrek.

Figure 9

We conducted​​ a perceptual evaluation to​​​‌ collect subjective scores for‌ visual distortions of generated‌​‌ 3D human animations.

Figure​​ 9: We conducted​​​‌ a perceptual evaluation to‌ collect subjective scores for‌​‌ visual distortions of generated​​ 3D human animations with​​​‌ respect to corresponding references,‌ which are the acquired‌​‌ 3D reconstructions of real​​ actors. We used the​​​‌ resulting “4DHumanPercept” dataset to‌ first analyse the factors‌​‌ influencing human motion realism,​​ and second, to learn​​​‌ a data-driven model called‌ “4DHumanQA” that predicts a‌​‌ perceptual score for 3D​​ human animation realism.

Virtual​​​‌ human animations have a‌ wide range of applications‌​‌ in virtual and augmented​​ reality. While automatic generation​​​‌ methods of animated virtual‌ humans have been developed,‌​‌ assessing their quality remains​​ challenging. Recently, approaches introducing​​​‌ task-oriented evaluation metrics have‌ been proposed, leveraging neural‌​‌ network training. However, quality​​ assessment measures for animated​​​‌ virtual humans that are‌ not generated with parametric‌​‌ body models have yet​​ to be developed. In​​​‌ this context, we introduced‌ in this work 11‌​‌ a first such quality​​ assessment measure leveraging a​​​‌ novel data-driven framework. First,‌ we generated a dataset‌​‌ of virtual human animations​​ together with their corresponding​​​‌ subjective realism evaluation scores‌ collected with a user‌​‌ study. Second, we used​​ the resulting dataset to​​​‌ learn predicting perceptual evaluation‌ scores. Results indicate that‌​‌ training a linear regressor​​ on our dataset results​​​‌ in a correlation of‌ 90%, which outperforms a‌​‌ state of the art​​ deep learning baseline.

8.9​​​‌ DepthLight: a Single Image‌ Lighting Pipeline for Seamless‌​‌ Integration of Virtual Objects​​ into Real Scenes

Participants:​​​‌ Raphaël Manus, Kebing‌ Xue, Samuel Boivin‌​‌ [contact], Marc Christie​​.

Figure 10

Overview of the​​​‌ method.

Figure 10:‌ Overview of our DepthLight‌​‌ pipeline. Blue dashed lines​​ represent the possible input​​​‌ points of our pipeline.‌ Our testing involved the‌​‌ whole pipeline using LDR​​ LFOV input images.

The​​​‌ paper 16 introduces DepthLight,‌ a method to estimate‌​‌ spatial lighting for photorealistic​​ Visual Effects (VFX) using​​​‌ a single image as‌ input. Previous techniques rely‌​‌ either on estimated or​​ captured light representations that​​​‌ fail to account for‌ localized lighting effects, or‌​‌ use simplified lights that​​ do not fully capture​​​‌ the complexity of the‌ illumination process.

DepthLight addresses‌​‌ these limitations by using​​​‌ a single LDR image​ with a limited field​‌ of view (LFOV) as​​ an input to compute​​​‌ an emissive texture mesh​ around the image (a​‌ mesh which generates spatial​​ lighting in the scene),​​​‌ producing a simple and​ lightweight 3D representation for​‌ photorealistic object relighting (see​​ Figure 10). First,​​​‌ an LDR panorama is​ generated around the input​‌ image using a photorealistic​​ diffusion-based inpainting technique, conditioned​​​‌ on the input image.​ An LDR to HDR​‌ network then reconstructs the​​ full HDR panorama, while​​​‌ an off-the-shelf depth estimation​ technique generates a mesh​‌ representation to finally build​​ a 3D emissive mesh.​​​‌ This emissive mesh approximates​ the bidirectional light interactions​‌ between the scene and​​ the virtual objects that​​​‌ is used to relight​ virtual objects placed in​‌ the scene. We also​​ exploit this mesh to​​​‌ cast shadows from the​ virtual objects on the​‌ emissive mesh, and add​​ these shadows to the​​​‌ original LDR image. This​ flexible pipeline can be​‌ easily integrated into different​​ VFX production workflows.

In​​​‌ our experiments, DepthLight shows​ that virtual objects are​‌ seamlessly integrated into real​​ scenes with a visually​​​‌ plausible estimation of the​ lighting. We compared our​‌ results to the ground​​ truth lighting using Unreal​​​‌ Engine, as well as​ to state-of-the-art approaches that​‌ use pure HDRi lighting​​ techniques. Finally, we validated​​​‌ our approach conducting a​ user evaluation over 52​‌ participants as well as​​ a comparison to existing​​​‌ techniques.

DepthLight has shown​ its limitations in terms​‌ of accuracy for the​​ estimation of the light​​​‌ sources, especially regarding complex​ scenes. We are now​‌ inverstigating a very different​​ approach through the AeX​​​‌ Enlight, based on Deep​ Learning and diffusion-based techniques,​‌ and also using Gaussian​​ Splatting.

8.10 New evaluation​​​‌ methods of persistent non-specific​ low back pain (PNSLBP)​‌ using locomotion paradigms.

Participants:​​ Anne-Hélène Olivier [contact].​​​‌

Figure 11

Illustration of the paradigms.​

Figure 11: Illustration​‌ of the different protocols​​ used to evaluate low​​​‌ back pain individuals.

This​ research activity has focused​‌ on developing novel assessment​​ approaches for individuals with​​​‌ chronic non-specific low back​ pain (cNSLBP), moving beyond​‌ traditional self-reported outcomes toward​​ functional, behavior-based evaluations grounded​​​‌ in locomotion–environment interactions. We​ performed a systematic review​‌ (6)of randomized​​ controlled trials highlighting that​​​‌ current clinical assessments in​ manual therapy predominantly rely​‌ on questionnaires targeting pain​​ intensity and perceived disability,​​​‌ with limited use of​ biomechanical or ecological markers.​‌ In parallel, we designed​​ experimental paradigms assessing navigation​​​‌ and decision-making during locomotion​ in interaction with environmental​‌ and social constraints. We​​ demonstrated that individuals with​​​‌ cNSLBP adopt more conservative​ and less socially modulated​‌ navigation strategies, accompanied by​​ slower walking speeds, when​​​‌ crossing apertures in the​ presence of situational and​‌ social challenges (7​​). In another study,​​​‌ we further showed that​ cNSLBP alters pedestrian–pedestrian collision​‌ avoidance strategies, with asymmetric​​ contributions to interaction resolution​​​‌ and a modulation of​ behavior by pain-related psychosocial​‌ factors (5).Complementary​​ work showed reduced adaptability​​​‌ and movement complexity in​ cNSLBP participants, quantified using​‌ entropy-based metrics during adaptive​​ gait tasks (20​​). Together, these studies​​​‌ support the relevance of‌ interaction-based locomotor paradigms to‌​‌ capture functional impairments in​​ cNSLBP and lay the​​​‌ groundwork for more ecologically‌ valid clinical evaluation tools.‌​‌

8.11 Effects of lifestyle​​ activity level on crowd​​​‌ navigation preferences and performances‌ in young adults.

Participants:‌​‌ Anne-Hélène Olivier [contact],​​ Julien Pettré.

Figure 12

Virtual​​​‌ crowd.

Figure 12:‌ Illustration of the virtual‌​‌ crowd used to evaluate​​ the effect of inactivity​​​‌ on navigation in complex‌ environment.

Navigating crowded environments‌​‌ is essential for safe​​ and efficient mobility in​​​‌ daily life. This study‌ 21, conducted within‌​‌ the SocNav associate team,​​ investigated how physical activity​​​‌ levels influence crowd navigation‌ preferences and performance in‌​‌ young adults. Fifteen physically​​ active and fifteen physically​​​‌ inactive participants navigated a‌ virtual park environment with‌​‌ varying crowd densities using​​ an immersive VR setup.​​​‌ Trajectories, walking speed, and‌ gaze behavior were recorded‌​‌ to assess navigation strategies.​​ While no group differences​​​‌ were observed during unobstructed‌ walking, physically inactive participants‌​‌ adopted more conservative strategies​​ in crowds, walking slower​​​‌ and choosing longer paths‌ with larger interpersonal gaps.‌​‌ When following an identical​​ path in a dense​​​‌ crowd, inactive participants showed‌ reduced walking speed during‌​‌ both the approach and​​ navigation phases. Eye-tracking data​​​‌ indicated that inactive participants‌ focused more on nearby‌​‌ agents, suggesting increased attentional​​ demands. Despite these behavioral​​​‌ differences, collision rates and‌ perceived task demands were‌​‌ similar across groups. Overall,​​ the findings suggest that​​​‌ physical inactivity affects confidence‌ and strategy during crowd‌​‌ navigation, with potential implications​​ for daily mobility and​​​‌ social participation.

8.12 GTAvatar:‌ Bridging Gaussian Splatting and‌​‌ Texture Mapping for Relightable​​ and Editable Gaussian Avatars​​​‌

Participants: Kevin Baert,‌ François Bourel, Marc‌​‌ Christie [contact].

Figure 13

The​​ overall pipeline for 3D​​​‌ head reconstruction using a‌ Texture-Gaussian representation.

Figure 13‌​‌: Our Texture-Gaussian splat​​ method that enables qualitative​​​‌ reconstruction and intuitive editing‌ of physically based rendering‌​‌ characteristics of a human​​ head, from a single​​​‌ monocular video. The result‌ can be re-rendered, re-animated‌​‌ and re-light, while conserving​​ the visual quality of​​​‌ the Gaussian Splat representation.‌

This research addresses the‌​‌ challenge of creating relightable​​ and editable photorealistic avatar​​​‌ models by combining two‌ complementary 3D representation paradigms:‌​‌ Gaussian splatting and texture​​ mapping. Gaussian splatting provides​​​‌ high-fidelity appearance reconstruction from‌ images but offers limited‌​‌ editability, while traditional mesh-based​​ representations enable intuitive editing​​​‌ at the cost of‌ visual realism. The proposed‌​‌ approach bridges these representations​​ by embedding Gaussian primitives​​​‌ within the UV space‌ of a template mesh,‌​‌ enabling the reconstruction of​​ continuous, editable material textures​​​‌ from a single monocular‌ video. A physically based‌​‌ reflectance model is incorporated​​ to support relighting, allowing​​​‌ the avatar’s appearance to‌ respond consistently to novel‌​‌ illumination conditions. Experimental results​​ demonstrate that this hybrid​​​‌ representation achieves high visual‌ quality while supporting intuitive‌​‌ appearance editing and relighting​​ without additional optimization steps.​​​‌ The method balances reconstruction‌ fidelity, relightability, and user-driven‌​‌ control, making it well​​ suited for graphics and​​​‌ virtual production workflows.

8.13‌ Pulp Motion: Framing-aware Multimodal‌​‌ Camera and Human Motion​​​‌ Generation

Participants: Robin Courant​, Marc Christie [contact]​‌.

Figure 14

An image that​​ shows a manifold surface​​​‌ and corresponding camera shots​ sampled from this surface.​‌

Figure 14: Our​​ dedicated motion diffusion network​​​‌ is able to properly​ identify the manifolds of​‌ character and camera motions​​ from large datasets, and​​​‌ enables relevant text-condtionned generated​ results that remain within​‌ the joint distribution.

This​​ research tackles the problem​​​‌ of jointly generating human​ motion and camera trajectories​‌ while preserving coherent on-screen​​ framing, a fundamental principle​​​‌ of cinematography that is​ largely ignored by existing​‌ generative approaches. Most prior​​ methods treat camera motion​​​‌ and human motion as​ independent modalities, leading to​‌ visually inconsistent compositions. The​​ proposed framework introduces on-screen​​​‌ framing as an explicit​ auxiliary modality that connects​‌ human pose and camera​​ motion. A shared latent​​​‌ space is learned using​ a multimodal autoencoder, where​‌ human motion and camera​​ trajectories are jointly embedded.​​​‌ A lightweight linear mapping​ aligns this shared representation​‌ with a framing latent,​​ ensuring compositional coherence during​​​‌ generation. To enable controllable​ synthesis, the method employs​‌ a latent diffusion process​​ decomposed into framing-aligned and​​​‌ framing-orthogonal components. A new​ dataset containing paired camera​‌ motions, human motions, and​​ textual descriptions is also​​​‌ introduced. Experimental results show​ improved framing quality and​‌ text-to-motion alignment compared to​​ state-of-the-art multimodal generation methods.​​​‌

8.14 MVAE: Motion-conditioned Variational​ Auto-Encoder for Tailoring Character​‌ Animations

Participants: Jean-Baptiste Bordier​​, Marc Christie [contact]​​​‌.

Figure 15

A VAE framework​ for conditionned motion generation.​‌

Figure 15: Overview​​ of our motion-VAE learning​​​‌ system that takes as​ input an original motion​‌ together with user inputs,​​ and generates an adpated​​​‌ motion, condtionned by features​ of the user input​‌ (amplitude, frequency, velocity).

This​​ research 13 focuses on​​​‌ simplifying the creation of​ diverse and expressive character​‌ animations through motion-driven control.​​ Instead of relying on​​​‌ textual prompts or predefined​ action labels, the proposed​‌ approach conditions animation generation​​ on continuous motion signals​​​‌ captured via virtual reality​ controllers. The Motion-conditioned Variational​‌ Auto-Encoder learns a latent​​ representation that encodes both​​​‌ global motion intent, such​ as action type, and​‌ local motion characteristics, including​​ speed, rhythm, and amplitude.​​​‌ By sampling this latent​ space, the system generates​‌ varied animation outputs that​​ remain consistent with the​​​‌ user’s input motion.The approach​ enables intuitive exploration of​‌ animation variations without extensive​​ manual keyframing, allowing animators​​​‌ to rapidly prototype and​ refine character movements.

8.15​‌ AKiRa: Augmentation Kit on​​ Rays for Optical Video​​​‌ Generation

Participants: Robin Courant​, Marc Christie [contact]​‌.

Figure 16

Effects on visual​​ features on the Plucker​​​‌ coordinates.

Figure 16:​ Optical effect overview. Visualization​‌ of various optical effects​​ proposed in our system​​​‌ —zoom, distortion, and bokeh—and​ their impacts on both​‌ the camera parameters (top​​ row) and visual output​​​‌ (bottom row). In addition,​ as with state-of-art techniques,​‌ we enable the control​​ of the camera motion.​​​‌

This research 18 addresses​ the lack of explicit​‌ control over camera motion​​ and optical parameters in​​​‌ text-conditioned video diffusion models.​ Although recent approaches achieve​‌ high visual fidelity, they​​ offer limited control over​​ cinematographic elements such as​​​‌ zoom, lens distortion, depth‌ of field, and focus‌​‌ transitions. The proposed framework,​​ AKiRa, augments existing video​​​‌ generation backbones with a‌ camera adapter based on‌​‌ a physically grounded camera​​ model. By modeling video​​​‌ formation at the ray‌ level, the system enables‌​‌ fine-grained control over focal​​ length, aperture, and lens​​​‌ distortion, allowing the synthesis‌ of cinematic effects such‌​‌ as zooms, fisheye distortion,​​ and bokeh. Experimental evaluations​​​‌ demonstrate that AKiRa supports‌ the composition of complex‌​‌ optical effects while outperforming​​ state-of-the-art controllable video generation​​​‌ methods in terms of‌ realism and visual quality.‌​‌

8.16 De l'immersion au​​ cinéma

Participants: Marc Christie​​​‌ [contact].

Figure 17

A man‌ in a spacesuit

Figure‌​‌ 17: Our recently​​ published book that explores​​​‌ the relation between immersion‌ and cinematography.

This research‌​‌ 19 examines immersion in​​ cinema as both a​​​‌ cognitive and a sensory‌ phenomenon shaping the spectator’s‌​‌ experience. Immersion is analyzed​​ through a dual perspective,​​​‌ encompassing mental engagement driven‌ by narrative absorption and‌​‌ physical immersion produced by​​ audiovisual technologies and exhibition​​​‌ environments. The work traces‌ the historical evolution of‌​‌ immersive cinematic practices, from​​ early panoramic and pre-cinematic​​​‌ experiences to contemporary digital‌ cinema and interactive media.‌​‌ It analyzes how technical​​ parameters such as camera​​​‌ mobility, sound spatialization, and‌ display technologies interact with‌​‌ narrative structures to influence​​ perception. By situating immersion​​​‌ within broader aesthetic and‌ epistemological frameworks, this study‌​‌ provides a structured understanding​​ of how cinematic technologies​​​‌ and storytelling techniques jointly‌ contribute to audience engagement.‌​‌

9 Bilateral contracts and​​ grants with industry

9.1​​​‌ Bilateral contracts with industry‌

Cifre InterDigital - Deep-based‌​‌ semantic representation of avatars​​ for virtual reality

Participants:​​​‌ Ludovic Hoyet [contact],‌ Philippe De Clermont Gallerande‌​‌.

The overall objective​​ of the PhD thesis​​​‌ of Philippe De Clermont‌ Gallerande, which started in‌​‌ February 2023, is to​​ explore novel approaches (including​​​‌ both full body and‌ facial elements) to enable‌​‌ both full body and​​ facial encoding and decoding​​​‌ for multi-user immersive experiences.‌ Objective is also to‌​‌ enable the evaluation of​​ the quality of experience.​​​‌ More specifically, one of‌ the focus is to‌​‌ propose solutions to represent​​ digital characters (avatars) with​​​‌ semantic-based approaches in a‌ context of multi-user immersive‌​‌ telepresence, that are compact,​​ plausible and simulatenously resiliant​​​‌ to data perturbation caused‌ by streaming. This PhD‌​‌ is conducted within the​​ context of the joint​​​‌ laboratory Nemo.ai between Inria‌ and InterDigital, and more‌​‌ specifically within the Ys.ai​​ project which is dedicated​​​‌ to exploring novel research‌ questions and applications in‌​‌ Virtual Reality. This work​​ is also conducted in​​​‌ collaboration between the two‌ Inria teams Hybrid and‌​‌ Virtus, as well as​​ with the Interactive Media​​​‌ team of InterDigital.

Cifre‌ InterDigital - Facial features‌​‌ from high quality cinema​​ footage

Participants: Marc Christie​​​‌ [contact], Kelian Baert‌.

The overall objective‌​‌ of the PhD thesis​​ of Kelian Baert (started​​​‌ in 2024, funded by‌ VFX company Mikros Image)‌​‌ is to explore novel​​ representations to extract facial​​​‌ features from high quality‌ cinema footage, and provide‌​‌ intuitive techniques to perform​​​‌ facial editing including shape,​ appearance and animation. More​‌ precisely, we search to​​ improve the controllability of​​​‌ learning-based techniques for editing​ photo-realistic faces in video​‌ sequences, aimed at the​​ visual effects for cinema.​​​‌ The aim is to​ accelerate post-production processes on​‌ faces by enabling an​​ artist to finely control​​​‌ different characteristics over time.​ There are numerous applications:​‌ rejuvenation and aging, make-up/tattooing,​​ strong modifications morphology (adding​​​‌ a 3rd eye, for​ example), replacing an understudy​‌ with the actor's face​​ by the actor's face,​​​‌ adjustments to the actor's​ acting. The PhD will​‌ rely on a threefold​​ approach: transfer of features​​​‌ from real to synthetic,​ editing in the synthetic​‌ domain on simplified representations,​​ and then to transfer​​​‌ the contents back to​ photorealistic sequences using GAN/Diffusion-based​‌ models to ensure visual​​ quality.

LCPP (PhD contract)​​​‌ - Immersive crowd simulation​ for the study and​‌ design of public spaces​​

Participants: Julien Pettré [contact]​​​‌, Ludovic Hoyet,​ Jordan Martin.

The​‌ overall objective of the​​ PhD thesis of Jordan​​​‌ Martin, started in November​ 2022, is to explore​‌ the use of Virtual​​ Reality to better design​​​‌ and assess public spaces.​ The VirtUs team specialises​‌ in the simulation, animation​​ and immersion of virtual​​​‌ crowds. The aim of​ this thesis is to​‌ explore new ways of​​ analysing crowd behaviours in​​​‌ real environments using new​ virtual reality technologies that​‌ allow users to be​​ directly immersed in digital​​​‌ replicas of these situations.​ More specifically, Jordan explores​‌ the technical conditions of​​ Virtual Reality experiments that​​​‌ lead to collecting realistic​ data. These conditions revolve​‌ around the visual representations​​ of virtual humans, as​​​‌ well as display conditions.​

CEA (PhD contract) -​‌ Generation and control of​​ virtual manikins using machine​​​‌ learning for the simulation​ of industrial processes using​‌ VR

Participants: Thomas Bouyer​​, Ludovic Hoyet [contact]​​​‌.

The overall objective​ of the PhD thesis​‌ of Thomas Bouyer, started​​ in January 2025 in​​​‌ collaboration with the CEA,​ is to explore how​‌ deep learning based physical​​ simulation approaches can be​​​‌ combined with ergonomic or​ visual metrics to facilitate​‌ the simulation of virtual​​ humans in industrial processes.​​​‌ In such contexts, human​ movements can be highly​‌ constrained by the industrial​​ environment, which currently impair​​​‌ realism (e.g., in terms​ of posture, effort and​‌ interaction with the environment).​​

9.2 Bilateral Grants with​​​‌ Industry

Vivo mobile phone​

Participants: Marc Christie [contact]​‌, Lezhong Wang,​​ Alice Phuing-ngoc.

The​​​‌ objective of the Vivo​ project (2025-27, 320k€) is​‌ to perform qualitative transfer​​ of cinematographic sequences to​​​‌ user-captured contents. The challenge​ is to identify the​‌ relevant visual, semantic and​​ geometric features that characterize​​​‌ qualitative camera trajectories, and​ to design a transfer​‌ technique between the extracted​​ features and the target​​​‌ scene, either represented using​ radiance based techniques (Gaussian​‌ Splats) or more implicit​​ visual represetnations such as​​​‌ VGGT.

10 Partnerships and​ cooperations

10.1 International initiatives​‌

10.1.1 Inria associate team​​ not involved in an​​​‌ IIL or an international​ program

Participants: Anne-Hélène Olivier​‌ [contact], Julien Pettré​​, Katja Zibrek,​​ Ludovic Hoyet.

SocNav​​​‌
  • Title:
    SocNav - Studying‌ complex social navigation with‌​‌ an innovative, co-developed immersive​​ platform
  • Partner Institution(s):
    • Université​​​‌ Laval Quebec, Canada
  • Date/Duration:‌
    started 2024 for 3‌​‌ years
  • Summary:
    The context​​ of the SocNav team​​​‌ is the study of‌ locomotor navigation in more‌​‌ socially complex environments representative​​ of daily life. When​​​‌ performing goal-directed walking, alone‌ or with others in‌​‌ public spaces, we are​​ continuously interacting with our​​​‌ dynamic surrounding environment, especially‌ avoiding collisions with other‌​‌ pedestrians. However, research to​​ date has mainly considered​​​‌ simple, pairwise interactions and‌ many questions remain. In‌​‌ particular, the combined roles​​ of anticipatory and reactive​​​‌ control underlying locomotor navigation‌ in more socially complex‌​‌ environments with multiple pedestrian​​ interactions should be carried​​​‌ out. This needs to‌ also consider the confounding‌​‌ effects of one’s physical​​ limitations due to physical​​​‌ activity level or neurological‌ deficits and for mode‌​‌ of transport (i.e., biped​​ vs wheeled). This work​​​‌ will require the means‌ to create protocols that‌​‌ allow flexible control over​​ environmental factors, something best​​​‌ provided through immersive virtual‌ reality (VR) for which‌​‌ both teams are experts.​​ Therefore, this project has​​​‌ 3 main objectives: 1.‌ Create and evaluate an‌​‌ immersive experimental platform to​​ be used for the​​​‌ study of social navigation‌ in complex social environments‌​‌ 2. Study and model​​ how environmental and personal​​​‌ factors affect the control‌ of navigation in complex‌​‌ social environments in healthy​​ populations 3. Study and​​​‌ model how neurological deficits‌ affect the control of‌​‌ navigation in complex social​​ environments. The parallel development​​​‌ of such an immersive‌ platform will solidify collaborations‌​‌ beyond the granting period​​ as well as provide​​​‌ a tool that can‌ have great potential for‌​‌ application. The findings from​​ the proposed collaborations will​​​‌ not only improve our‌ understanding of the trade-offs‌​‌ in anticipatory and reactive​​ control for locomotor navigation​​​‌ of complex social environments,‌ but will also significantly‌​‌ contribute to improving assessment​​ and training tools, and​​​‌ the development of intelligent‌ mobility aids (smart wheelchairs).‌​‌

10.2 International research visitors​​

10.2.1 Visits of international​​​‌ scientists

Other international visits‌ to the team
Krista‌​‌ Best
  • Status
    Adjunct professor​​
  • Institution of origin:
    Université​​​‌ Laval, CIRRIS
  • Country:
    Canada‌
  • Dates:
    Sept 22 -Oct‌​‌ 31, 2025
  • Context of​​ the visit:
    Preparation of​​​‌ an experiment about immersive‌ navigation within a virtual‌​‌ crowd in traumatic brain​​ injury patients, discussion about​​​‌ future projects.
  • Mobility program/type‌ of mobility:
    Invited Professor‌​‌ program, University of Rennes​​ 2
Angelo Silvino
  • Status​​​‌
    PhD Candidate
  • Institution of‌ origin:
    University of Campania‌​‌ “Luigi Vanvitelli”
  • Country:
    Italy​​
  • Dates:
    Sept 2025-March 2026​​​‌
  • Context of the visit:‌
    Design and conduct an‌​‌ experiment about the role​​ of perceived self-efficacy, belonging,​​​‌ and psychological distance in‌ the ecological transition
  • Mobility‌​‌ program/type of mobility:
    PhD​​ scholarship from University of​​​‌ Campania National Recovery and‌ Resilience Plan (PNRR)
Francisco‌​‌ Ortega
  • Status
    Associate Professor​​
  • Institution of origin:
    Colorado​​​‌ State University
  • Country:
    USA‌
  • Dates:
    July 8-9, 2025‌​‌
  • Context of the visit:​​
    Visit of the team​​​‌ and presentation of his‌ research
  • Mobility program/type of‌​‌ mobility:
    Own budget
Jean-Bernard​​​‌ Hayet
  • Status
    Senior Research​ Scientist
  • Institution of origin:​‌
    CIMAT, department of Computer​​ Science
  • Country:
    Mexico
  • Dates:​​​‌
    Dec 15-19, 2025
  • Context​ of the visit:
    Ongoing​‌ collaboration on crowd simulation​​ topics, ans discussions for​​​‌ future collaborations in the​ frame of a sabbatical​‌ research stay
  • Mobility program/type​​ of mobility:
    Own funding​​​‌
Vinu Kamalasanan
  • Status
    Post​ Doc
  • Institution of origin:​‌
    TU Clausthal
  • Country:
    Germany​​
  • Dates: Sept 1-3, 2025​​​‌
  • Context of the visit:​
    Discussion about future collaborations​‌ on pedestrian-bicycle interactions.
  • Mobility​​ program/type of mobility:
    Tom​​​‌ Troscianko Travel Award

10.2.2​ Visits to international teams​‌

Research stays abroad
  • Céline​​ Finet
    stayed for 2​​​‌ months at the CIMAT​ in Huanajuato (Mexico), working​‌ with Jean-Bernard Hayet. She​​ then stayed for 2​​​‌ months at University of​ California, Riverside, to work​‌ with Ioannis Karamouzas.
  • Anne-Hélène​​ Olivier, Julien Pettré, Pierre​​​‌ Vauclin, Aline Hufschmitt
    stayed​ a week at the​‌ CIRRIS, Laval University, Québec.​​ We discuss on the​​​‌ advancements of the SocNav​ associate team and open​‌ discussion for European Funding​​ applications.

10.3 European initiatives​​​‌

10.3.1 Horizon Europe

META-TOO​

Participants: Katja Zibrek.​‌

META-TOO project on cordis.europa.eu​​

  • Title:
    A transfer of​​​‌ knowledge and technology for​ investigating gender-based inappropriate social​‌ interactions in the Metaverse​​
  • Duration:
    From June 1,​​​‌ 2024 to May 31,​ 2027
  • Partners:
    • INSTITUT NATIONAL​‌ DE RECHERCHE EN INFORMATIQUE​​ ET AUTOMATIQUE (INRIA), France​​​‌
    • ETHNIKO KAI KAPODISTRIAKO PANEPISTIMIO​ ATHINON (UOA), Greece
    • FUNDACIO​‌ DE RECERCA CLINIC BARCELONA-INSTITUT​​ D INVESTIGACIONS BIOMEDIQUES AUGUST​​​‌ PI I SUNYER (IDIBAPS-CERCA),​ Spain
  • Inria contact:
    Ferran​‌ Argelaguet (Hybrid)
  • Coordinator:
    Maria​​ Roussou (UOA)
  • Summary:
    The​​​‌ META-TOO proposal underscores the​ knowledge and skills transfer​‌ from two distinguished European​​ institutions, INRIA and IDIBAPS,​​​‌ each renowned for its​ research contributions in the​‌ digital forefront, to the​​ National and Kapodistrian University​​​‌ of Athens (NKUA), Greece,​ serving as the coordinating​‌ institution representing a Widening​​ country (Greece). Specifically, both​​​‌ INRIA (The French National​ Institute for Research in​‌ Computer Science and Automation)​​ and IDIBAPS (Fundaci de​​​‌ Recerca Clnic Barcelona in​ Spain) have earned global​‌ recognition for their outstanding​​ contributions to Extended Reality​​​‌ (XR) research. It is​ precisely within this domain​‌ that we have elected​​ to focus the support​​​‌ of INRIA and IDIBAPS​ (henceforth called mentors) for​‌ the National and Kapodistrian​​ University of Athens (coordinator),​​​‌ with a concerted effort​ aimed at reinforcing research​‌ management and administrative competencies,​​ alongside enhancing research and​​​‌ innovation capabilities. The META-TOO​ also has two important​‌ research axes: a) to​​ study and design interaction​​​‌ techniques for mitigating inappropriate​ social behaviour in Social​‌ Virtual Reality (SVR) and​​ b) to conduct studies​​​‌ in harassment prevention through​ enhancing empathy by perspective-taking​‌ and bystander behaviour. The​​ research combines interdisciplinary expertise​​​‌ and strengths of all​ three partners involved in​‌ the META-TOO project.

10.4​​ National initiatives

Défi Ys.AI​​​‌

Participants: Ludovic Hoyet [contact]​, Philippe De Clermont​‌ Gallerande.

With the​​ recent annoucements about massive​​​‌ investments on the Metaverses,​ which are seen as​‌ the future of the​​ social and professional immersive​​​‌ communication for the emergent​ AI-based e-society, there is​‌ a need for the​​ development of dedicated metaverse​​ technologies and associated representation​​​‌ formats. In this context,‌ the objective of this‌​‌ joint project between Inria​​ and InterDigital is to​​​‌ focus on the representation‌ formats of digital avatars‌​‌ and their behavior in​​ a digital and responsive​​​‌ environment. In particular, the‌ primary challenge tackled in‌​‌ this project consists in​​ solving the uncanny valley​​​‌ effect to provide users‌ with a natural and‌​‌ lifelike social interaction between​​ real and virtual actors,​​​‌ leading to full engagement‌ in those future metaverse‌​‌ experiences.

ANR Animation Conductor​​

Participants: Marc Christie [contact]​​​‌, Théo Gérard,‌ Ludovic Hoyet.

  • Duration:‌​‌
    Oct 2023 - Oct​​ 2027
  • Team funding:
    286k€​​​‌
  • Partners:
    • LiX in Polytechnique‌
    • Dada Animation company
  • Summary:‌​‌
    The fundamental idea of​​ the ANR Animation Conductor​​​‌ project is to (i)‌ express simultaneous multimodal inputs‌​‌ as high-level animation principles​​ into a motion characteristics​​​‌ space, (ii) exploit spatial‌ and temporal characteristics of‌​‌ the input signals to​​ edit existing animations using​​​‌ learning techniques inspired by‌ style transfer, (iii) combine‌​‌ the style transfer techniques​​ with authoring constraints such​​​‌ as physics-based and (iv)‌ co-design interactive tools with‌​‌ creative artists to exploit​​ them in industrial pipelines.​​​‌ More precisely, we first‌ aim at providing new‌​‌ ways of understanding on​​ which part of an​​​‌ animation a “conductor” (i.e.‌ animator or supervisor) is‌​‌ working, to build a​​ correlation between different input​​​‌ signals and output animation‌ curves by designing a‌​‌ dataset with experienced animators.​​ Secondly, we aim at​​​‌ designing new computational models‌ to efficiently modify 3D‌​‌ animations from mimics through​​ the use of individual​​​‌ or combined input modalities‌ - namely records of‌​‌ voices and sounds, video​​ records of body parts​​​‌ gestures, and 3D space-time‌ acquisition from lightweight VR‌​‌ worn or mounted systems,​​ while not requiring full​​​‌ MOCAP infrastructure. To this‌ end, we propose to‌​‌ develop novel methods able​​ to extract the spatial​​​‌ and temporal authoring potential‌ of these modalities into‌​‌ a motion characteristics space,​​ as well as exploring​​​‌ new ways to leverage‌ the use of combined‌​‌ modalities to ease 3D​​ animation control, inspired from​​​‌ style-transfer techniques in animation,‌ and to compose with‌​‌ authoring constraints. This project​​ targets direct applications and​​​‌ prototypes, starting with our‌ open-source one, within French‌​‌ animation studios for the​​ refinement of existing animations​​​‌ for shape and character‌ subparts.
ANR VROOM

Participants:‌​‌ Ludovic Hoyet, Julien​​ Pettré [contact], Anne-Hélène​​​‌ Olivier, Stéphane Donikian‌.

  • Duration:
    42 months,‌​‌ 2026-2029
  • Team funding:
    205k€​​
  • Partners:
    SNCF, Univ. Gustave​​​‌ Eiffel, Inocess
  • Summary:
    The‌ VROOM project (Virtual Reality‌​‌ to Optimize crOwd Management)​​ aims to develop an​​​‌ innovative methodology to improve‌ passenger flow management in‌​‌ railway stations by combining​​ field observation, IoT sensing,​​​‌ and virtual reality. Current‌ crowd management practices remain‌​‌ largely empirical and are​​ limited by legal, technical,​​​‌ and observational constraints. VROOM‌ addresses these limitations by‌​‌ focusing on the acquisition​​ of situation-specific, fine-grained behavioral​​​‌ data. The project proposes‌ the creation of immersive‌​‌ digital twins of train​​ stations, directly grounded in​​​‌ real-world measurements and populated‌ with realistic virtual passengers.‌​‌ These digital twins enable​​​‌ controlled experimental studies of​ individual and collective behaviors​‌ under dense crowd conditions.​​ A key use case​​​‌ concerns automatic ticket control​ lines, which are major​‌ sources of congestion and​​ discomfort. Through VR experiments,​​​‌ VROOM investigates perceptual, cognitive,​ and behavioral factors underlying​‌ passenger navigation and decision-making.​​ The outcomes of these​​​‌ studies are then transferred​ back to real stations​‌ and evaluated in ecological​​ conditions. By tightly coupling​​​‌ field data, immersive simulation,​ and behavioral experimentation, VROOM​‌ seeks to provide scientifically​​ grounded and operational tools​​​‌ for safer, more efficient,​ and more comfortable crowd​‌ management.
AeX Enlight

Participants:​​ Samuel Boivin [contact],​​​‌ Marc Christie, Kebing​ Xue.

Coordinator: Samuel​‌ Boivin

Duration: 36 months​​ (Sept 2025-Sept 2028)

This​​​‌ project focuses on the​ automatic estimation of the​‌ lighting conditions of a​​ real scene in order​​​‌ to seamlessly integrate virtual​ elements in a visually​‌ indistinguishable manner. To this​​ end, we will investigate​​​‌ the joint estimation of​ light sources and materials​‌ using Deep Learning and​​ probabilistic methods, as well​​​‌ as a novel error​ metric for assessing the​‌ qualitative level of photo-realism​​ achieved.

DSR IPiC

Participants:​​​‌ Anne-Hélène Olivier [contact],​ Ludovic Hoyet, Julien​‌ Pettré, Stéphane Donikian​​.

  • Duration:
    36 months,​​​‌ 2025-2027
  • Team funding:
    130​ k€
  • Partners:
    Université Gustave​‌ Eiffel, Rennes Métropole
  • Summary:​​
    IPiC addresses current challenges​​​‌ related to the growing​ use of active mobility​‌ modes. As walking and​​ cycling increasingly coexist in​​​‌ shared urban spaces, conflicts​ between pedestrians and cyclists​‌ raise safety and comfort​​ concerns. The project aims​​​‌ to better understand the​ decision-making processes and adaptive​‌ movement strategies of both​​ users during such interactions.​​​‌ IPiC adopts an innovative​ experimental approach combining real-world​‌ observations and controlled experiments​​ both in real environment​​​‌ and in immersive virtual​ reality. Urban field studies​‌ conducted with local authorities​​ will be used to​​​‌ identify representative interaction scenarios,​ which will then be​‌ reproduced in coupled pedestrian​​ and bicycle simulators. Multidimensional​​​‌ data, including trajectories, gaze​ behavior, perceived risk, and​‌ perceived priority, will be​​ collected and analyzed. The​​​‌ project ultimately seeks to​ inform urban design and​‌ policy decisions while contributing​​ to the development of​​​‌ realistic pedestrian and cyclist​ interaction models for virtual​‌ environments.
DSR PERCEPT-PIETON

Participants:​​ Anne-Hélène Olivier [contact].​​​‌

  • Duration:
    36 months, 2025-2027​
  • Team funding:
    27k€
  • Partners:​‌
    Université Gustave Eiffel, Aix​​ Marseille Université
  • Summary:
    PERCEPT-PIETON​​​‌ addresses the growing safety​ challenges involving vulnerable road​‌ users, particularly pedestrians. Despite​​ overall progress in road​​​‌ safety, pedestrian fatalities, especially​ among older adults and​‌ children, remain a critical​​ issue, most often occurring​​​‌ during street crossings. While​ pedestrian behavior has been​‌ extensively studied, the perceptual,​​ cognitive, and motor mechanisms​​​‌ underlying drivers’ and cyclists’​ responses to pedestrians remain​‌ poorly understood. The project​​ aims to investigate how​​​‌ drivers and cyclists perceive​ and adapt their behavior​‌ when confronted with pedestrians​​ intending to cross the​​​‌ road. To achieve this,​ PERCEPT-PIETON relies on immersive​‌ virtual reality and the​​ use of biologically realistic​​​‌ pedestrian avatars generated from​ motion capture data. The​‌ work plan is organized​​ into three phases: (1)​​ building a library of​​​‌ pedestrian digital twins with‌ diverse movement characteristics, (2)‌​‌ developing configurable urban virtual​​ environments, and (3) conducting​​​‌ controlled experiments to measure‌ decision-making, speed regulation, and‌​‌ visual strategies of drivers​​ and cyclists. The project​​​‌ seeks to produce actionable‌ scientific knowledge for public‌​‌ decision-makers and to deliver​​ an open-access VR tool​​​‌ for research, training, and‌ awareness purposes.

10.5 Regional‌​‌ initiatives

Créativité Croisée (Rennes​​ Métropole) - Voyage du​​​‌ Geste

Participants: Anne-Hélène Olivier‌ [contact].

  • Duration:
    12‌​‌ months, 2025
  • Team funding:​​
    7k€
  • Partners:
    Centre Eugène​​​‌ Marquis, Laboratoire M2S (Univ‌ Rennes 2), artists: Julien‌​‌ Lomet and Pierre Huygue​​
  • Summary:
    Voyage du Geste​​​‌ is a multidisciplinary project‌ exploring the use of‌​‌ immersive virtual reality (VR)​​ to support physical activity​​​‌ and well-being in patients‌ with advanced or metastatic‌​‌ breast cancer. Although physical​​ activity is now recognized​​​‌ as a key therapeutic‌ tool in oncology care,‌​‌ these patients face major​​ barriers to movement, including​​​‌ fatigue, pain, anxiety, reduced‌ upper-limb mobility, and fear‌​‌ of movement. In parallel,​​ VR has emerged as​​​‌ a promising medium to‌ promote motivation, engagement, and‌​‌ safe re-engagement in movement​​ through immersive and adaptive​​​‌ environments. The project aims‌ to (1) develop an‌​‌ artistic immersive VR experience​​ tailored to patients’ needs​​​‌ through a co-construction process,‌ and (2) assess the‌​‌ feasibility and acceptability of​​ this experience during two​​​‌ immersive sessions conducted within‌ the “AVANCER AVEC” workshops‌​‌ at the Eugène Marquis​​ Cancer Center. This exploratory​​​‌ work is intended to‌ lay the foundations for‌​‌ a larger clinical project​​ investigating the therapeutic use​​​‌ of VR to enhance‌ mobility and well-being. The‌​‌ project is built on​​ an interdisciplinary collaboration involving​​​‌ digital artists, movement science‌ and health researchers, VR‌​‌ specialists, and healthcare professionals.​​ Its originality lies in​​​‌ the unique integration of‌ digital art, immersive VR,‌​‌ and movement sciences within​​ a patient-centered, co-designed therapeutic​​​‌ approach.
Inno R&D -‌ LUV

Participants: Marc Christie‌​‌ Olivier [contact], Kelian​​ Baert, Francois Bourel​​​‌.

  • Duration:
    24 months,‌ 2025-2026
  • Team funding:
    182k€‌​‌
  • Partners:
    Company EMOVA based​​ in Cesson-Sevigne
  • Summary:
    The​​​‌ purpose of the LUV‌ project is to improve‌​‌ the state of the​​ art in automated 3D​​​‌ reconstruction of Avatars from‌ a few view inputs‌​‌ (typically 3 to 5​​ images). The problem is​​​‌ addressed by building a‌ large latent representation of‌​‌ avatar heads from synthetic​​ data, and then inverse​​​‌ optimizing the latent code‌ from the few views,‌​‌ before fine-tuning the results.​​ Our novelty stands in​​​‌ the modality to represent‌ and train Gaussian Splats‌​‌ by using feature-conditionned MLPs.​​ Results will be integrated​​​‌ in the commercial solution‌ of the EMOVA company.‌​‌

11 Dissemination

Participants: Julien​​ Pettré, Anne-Hélène Olivier​​​‌, Samuel Boivin,‌ Marc Christie, Katja‌​‌ Zibrek, Ludovic Hoyet​​, Stéphane Donikian,​​​‌ Aline Hufschmitt.

11.1‌ Promoting scientific activities

11.1.1‌​‌ Scientific events: organisation

General​​ chair, scientific chair
  • Anne-Hélène​​​‌ Olivier: co-general chair of‌ IEEE Virtual Reality 2025‌​‌ Conference, Saint-Malo, France
  • Marc​​ Christie: co-program chair of​​​‌ Pacific Graphics 2025, Taipei,‌ Taiwan
  • Marc Christie: co-chair‌​‌ of Expressive 2025, London,​​​‌ UK
Member of the​ organizing committees
  • Ludovic Hoyet:​‌ Co-organizer of the Workshop​​ “Next Generation of Avatars”,​​​‌ IEEE Virtual Reality 2025,​ Saint-Malo, France
  • Ludovic Hoyet:​‌ Environmental Impact Reduction and​​ Awareness Co-Chair, IEEE Virtual​​​‌ Reality 2025, Saint-Malo, France​
  • Ludovic Hoyet: Diversity, Equity,​‌ Inclusion, and Accessibility Co-Chair,​​ IEEE Virtual Reality 2025,​​​‌ Saint-Malo, France
  • Julien Pettré:​ Social Events Co-Chair, IEEE​‌ Virtual Reality 2025, Saint-Malo,​​ France
  • Anne-Hélène Olivier, Julien​​​‌ Pettré, Katja Zibrek: Co-organizers​ of the Workshop "Virtual​‌ Humans and Crowds in​​ Immersive Environments", IEEE Virtual​​​‌ Reality 2025, Saint-Malo, France​
  • Anne-Hélène Olivier: co-organizer of​‌ the workshop on XR​​ Accessibility, IEEE Virtual Reality​​​‌ 2025, Saint-Malo, France
  • Anne-Hélène​ Olivier: Co-organizer of the​‌ Symposium "I am my​​ environment: Pushing the theories​​​‌ of adaptive locomotor control",​ International Society of Posture​‌ and Gait Research (ISPGR)​​ 2025, Maastricht, Netherlands.

11.1.2​​​‌ Scientific events: selection

Chair​ of conference program committees​‌
  • Julien Pettré: Editor for​​ the IEEE/RSJ International Conference​​​‌ on Intelligent Robots and​ Systems (IROS) 2025 Conference​‌
Member of the conference​​ program committees
  • Marc Christie:​​​‌ Pacific Graphics 2025, ACM​ Siggraph Asia 2025, CVMP​‌ 2025
  • Ludovic Hoyet: ACM​​ Siggraph (Conflict of Interest​​​‌ committee), ACM SIGGRAPH Symposium​ on Interactive 3D Graphics​‌ and Games 2025, ACM​​ Symposium on Applied Perception​​​‌ 2025, ACM Symposium on​ Computer Animation 2025, IEEE​‌ Virtual Reality 2026, ACM​​ Motion Interactions and Games​​​‌ 2025.
  • Katja Zibrek: IEEE​ Virtual Reality 2026 (committee​‌ and supercommittee), ACM Symposium​​ on Applied Perception (SAP)​​​‌ 2025, IEEE International Symposium​ on Mixed and Augmented​‌ Reality (ISMAR) 2025, ACM​​ Motion Interactions and Games​​​‌ (MIG) 2025, Computer Animation​ and Social Agents (CASA)​‌ 2025, Ars Electronica Expanded​​ conference 2025
  • Anne-Hélène Olivier:​​​‌ ACM Symposium on Applied​ Perception 2025, IEEE Virtual​‌ Reality 2026, ACM VRST​​ 2025, XR en Mouvement​​​‌ 2025
  • Julien Pettré: ACM​ SIGGRAPH ASIA 2025, ACM​‌ Motion Interactions and Games​​ (MIG) 2025, ACM Symposium​​​‌ on Applied Perception (SAP)​ 2025, Pedestrian and Evacuation​‌ Dynamics (PED) 2025
Reviewer​​
  • Marc Christie: ACM SIGGRAPH​​​‌ 2025, ACM SIGGRAPH Asia​ 2025, CVPR 2025, 3DV​‌ 2025
  • Julien Pettré: IEEE​​ Virtual Reality 2026, International​​​‌ Conference on Extended Reality​ (ICXR) 2025,
  • Ludovic Hoyet:​‌ ACM Conference on Human​​ Factors in Computing Systems​​​‌ (CHI), IEEE International Symposium​ on Mixed and Augmented​‌ Reality (ISMAR), ACM Siggraph​​ Asia 2024
  • Katja Zibrek:​​​‌ ACM Symposium on Virtual​ Reality Software and Technology​‌ (VRST) 2025
  • Anne-Hélène Olivier:​​ IEEE International Symposium on​​​‌ Mixed and Augmented Reality​ (ISMAR), International Conference on​‌ extended Reality (ICXR 2025)​​
Conference award committees
  • Anne-Hélène​​​‌ Olivier: Co-chair of the​ ACM Symposium on Computer​‌ Animation 2025 award committee​​

11.1.3 Journal

Member of​​​‌ the editorial boards
  • Ludovic​ Hoyet: Associate Editor for​‌ ACM Transactions on Graphics​​ and Computer Graphics Forum.​​​‌
  • Anne-Hélène Olivier: Associate editor​ for IEEE Transactions of​‌ Visualization and Computer Graphics​​ (TVCG), and for Computers​​​‌ & Graphics
Reviewer -​ reviewing activities
  • Ludovic Hoyet:​‌ IEEE Transactions on Visualization​​ and Computer Graphics (TVCG)​​​‌
  • Marc Christie: Computers &​ Graphics
  • Julien Pettré: Physica​‌ A, Computer Graphics Forum​​
  • Anne-Hélène Olivier: International Journal​​​‌ of Human - Computer​ Studies, Computers in Human​‌ Behaviours
  • Katja Zibrek: IEEE​​ Transactions on Visualization and​​ Computer Graphics (TVCG), Computers​​​‌ and Graphics, Plos One,‌ Scientific Reports, International Journal‌​‌ of Human-Computer Studies (IJHCS)​​

11.1.4 Invited talks

  • Anne-Hélène​​​‌ Olivier: Virtual reality and‌ complex adaptive behaviours, Human-Centered‌​‌ Technological Innovation - A​​ new HUB for future​​​‌ technologies. Università degli Studi‌ della Campania, Italy, June‌​‌ 9, 2025.
  • Anne-Hélène Olivier:​​ Se déplacer dans des​​​‌ espaces publics : variables‌ de contrôle des trajectoires‌​‌ locomotrices, enjeux méthodologiques et​​ perspectives ouvertes par la​​​‌ réalité virtuelle. Séminaire de‌ la Commission ARPEGE Réalité‌​‌ Virtuelle, Augmentée et Mixte​​ - La Réalité Virtuelle​​​‌ dans les Sciences du‌ Mouvement Humain. Champs sur‌​‌ Marne, France, April 1st​​ 2025.

11.1.5 Leadership within​​​‌ the scientific community

  • Anne-Hélène‌ Olivier: Chair of the‌​‌ ACM Symposium on Applied​​ Perception Steering Committee

11.1.6​​​‌ Scientific expertise

  • Anne-Hélène Olivier:‌ Initiatives d'Excellence - Rayonnement‌​‌ International 2025, Grenoble

11.1.7​​ Research administration

  • Ludovic Hoyet​​​‌ is in charge of‌ the “Virtual Reality, Virtual‌​‌ Humans, Interactions and Robotics”​​ department of the IRISA​​​‌ laboratory (Institut de Recherche‌ en Informatique et Systèmes‌​‌ Aléatoires). This department includes​​ four Inria teams (Combo,​​​‌ Rainbow, Seamless, Virtus) and‌ is aligned with one‌​‌ of the strategic objectives​​ of the Inria Rennes​​​‌ centre described in the‌ Inria COP (i.e., “humans-robots-virtual‌​‌ worlds interactions”).
  • Samuel Boivin​​ is the Head of​​​‌ the program 'Virtual Worlds'‌ of the Program Agency‌​‌ driven by INRIA.

11.2​​ Teaching - Supervision -​​​‌ Juries - Educational and‌ pedagogical outreach

11.2.1 Teaching‌​‌

  • blackMaster: Marc Christie, Head​​ of Master 2 Ingénierie​​​‌ Logicielle (45 students), University‌ of Rennes, France
  • blackMaster:‌​‌ Marc Christie, "Multimedia Mobile",​​ Master 2, leader of​​​‌ the module, 32h (IL)‌ + 32h (Miage), Computer‌​‌ Science, University of Rennes,​​ France
  • blackMaster: Marc Christie,​​​‌ "Projet Industriel Transverse", Master‌ 2, 32h, leader of‌​‌ the module, Computer Science,​​ University of Rennes, France​​​‌
  • Master: Marc Christie, "Modelistion‌ Animation Rendu", Master 2,‌​‌ 16h, leader of the​​ module, Computer Science, University​​​‌ of Rennes, France
  • Master:‌ Marc Christie, "Web Engineering",‌​‌ Master 1, 16h, leader​​ of the module, Computer​​​‌ Science, University of Rennes,‌ France
  • Master: Marc Christie,‌​‌ "Advanced Computer Graphics", Master​​ 1, 10h, leader of​​​‌ the module, Computer Science,‌ ENS, France
  • Master: Marc‌​‌ Christie, "Motion for Animation​​ and Robotics", Master 2​​​‌ SIF, Computer Science, France‌
  • Master : Ludovic Hoyet,‌​‌ Motion Analysis and Gesture​​ Recognition, 12h, INSA Rennes,​​​‌ France
  • Master : Ludovic‌ Hoyet, Computer Graphics, 8h,‌​‌ Ecole Normale Supérieure de​​ Rennes, France
  • Master :​​​‌ Ludovic Hoyet, Réalité Virtuelle‌ pour l'Analyse Ergonomique, Master‌​‌ Ingénierie et Ergonomie des​​ Activités Physique, 21h, University​​​‌ Rennes 2, France
  • Master‌ : Aline Hufschmitt, Using‌​‌ Unreal Engine for military​​ training simulation creation, 24h,​​​‌ Académie Militaire de Saint-Cyr‌ Coëtquidan, France
  • Master :‌​‌ Aline Hufschmitt, Multi-user LAN​​ simulation under Unreal Engine,​​​‌ 24h, Académie Militaire de‌ Saint-Cyr Coëtquidan, France
  • Master‌​‌ : Aline Hufschmitt, Artificial​​ intelligence for simulating AMI/ENI​​​‌ behavior under Unreal Engine,‌ 30h, Académie Militaire de‌​‌ Saint-Cyr Coëtquidan, France
  • Master​​ : Aline Hufschmitt, Applied​​​‌ project: Unreal simulation for‌ visualizing blue team/red team‌​‌ training in a cyber​​ range, 24h, Académie Militaire​​​‌ de Saint-Cyr Coëtquidan, France‌
  • Master : Aline Hufschmitt,‌​‌ Adrenaline Rush Project, 50h,​​​‌ Académie Militaire de Saint-Cyr​ Coëtquidan, France
  • Licence :​‌ Aline Hufschmitt, C programming,​​ 100h, Académie Militaire de​​​‌ Saint-Cyr Coëtquidan, France
  • Master​ : Anne-Hélène Olivier, co-leader​‌ of the APPCM Master​​ (50 students) "Activités Physiques​​​‌ et Pathologies Chroniques et​ Motrices", STAPS, University Rennes2,​‌ France
  • Master : Anne-Hélène​​ Olivier, "Recueil et traitement​​​‌ des données", 26H, Master​ 1 and 2 APPCM/IEAP/EOPS,​‌ University Rennes2, France
  • Master​​ : Anne-Hélène Olivier, "Méthodologie​​​‌ de la recherche et​ accompagnement de stage", 15H,​‌ Master 1 and 2​​ APPCM, University Rennes2, France​​​‌
  • Licence : Anne-Hélène Olivier,​ "Analyse cinématique du mouvement",​‌ 100H , Licence 1,​​ University Rennes 2, France​​​‌
  • Master : Katja Zibrek,​ supervision of students' internship​‌ abroad program, Ecole supérieure​​ d'ingénieurs de Rennes (ESIR),​​​‌ 15h, University Rennes 2,​ France
  • Bachelors : Katja​‌ Zibrek, études pratiques, 3rd​​ year, 15h, Institut National​​​‌ des Sciences Appliquées de​ Rennes (INSA), France

11.2.2​‌ Supervision

  • PhD defended (beginning​​ Nov. 2020, defended July​​​‌ 2025): Emilie Leblong, Prise​ en compte des interactions​‌ sociales dans un simulateur​​ de conduite de fauteuil​​​‌ roulant électrique en réalité​ virtuelle : favoriser l'apprentissage​‌ pour une mobilité inclusive,​​ Anne-Hélène Olivier, Marie Babel​​​‌ (Rainbow team)
  • PhD defended​ (beginning Nov. 2021, defended​‌ June 2025): Rim Rekik​​ Dit Nekhili, Learning and​​​‌ evaluating 3D human motion​ synthesis, Anne-Hélène Olivier, Stefanie​‌ Wuhrer (Morpheo team).
  • PhD​​ in progress (beginning Oct.​​​‌ 2021): Xiaoyuan Wang, Realistic​ planning of hand motions,​‌ with Marc Christie, Adnane​​ Boukhayma.
  • PhD in progress​​​‌ (beginning Oct. 2022): Jordan​ Martin, Simulation immersive de​‌ foule pour l’étude et​​ l’aménagement de lieux destinés​​​‌ à accueillir du public,​ Ludovic Hoyet, Jean-Luc Paillat,​‌ Julien Pettré, Etienne Pinsard.​​
  • PhD in progress (beginning​​​‌ Oct. 2022): Alexis Jensen,​ Simulation de foule dense​‌ par modélisation dynamique, Julien​​ Pettré, Charles Pontonnier (Combo​​​‌ team).
  • PhD in progress​ (beginning Feb. 2023): Philippe​‌ De Clermont Gallerande (CIFRE​​ InterDigital), Deep-based semantic representation​​​‌ of avatars for virtual​ reality, Ferran Argelaguet (Seamless​‌ team), Quentin Avril (InterDigital),​​ Philippe-Henri Gosselin (InterDigital), Ludovic​​​‌ Hoyet.
  • PhD in progress​ (beginning Feb. 2023): Tony​‌ Wolff, Creating socially reactive​​ virtual characters for enhanced​​​‌ social interactions in Virtual​ Reality, Ludovic Hoyet, Anne-Hélène​‌ Olivier, Julien Pettré, Katja​​ Zibrek.
  • PhD in progress​​​‌ (beginning Sept. 2023): Celine​ Finet, Peuplement de scène​‌ par simulation de foule​​ basée apprentissage, Julien Pettré.​​​‌
  • PhD in progress (beginning​ Oct. 2023): Kelian Baert,​‌ Face Editing for Digital​​ Visual Effects in Film​​​‌ Production, with Marc Christie,​ Adnane Boukhayma.
  • PhD in​‌ progress (beginning Oct. 2023):​​ Arthur Audrain, Creating digital​​​‌ tools to mitigate harassement​ in the Metaverse, with​‌ Katja Zibrek and Ferran​​ Argelaguet.
  • PhD in progress​​​‌ (beginning Jan. 2024): Thomas​ Bouyer, Generation and control​‌ of virtual manikins using​​ machine learning for the​​​‌ simulation of industrial processes​ using VR, with Laurent​‌ Dolle (CEA) and Vincent​​ Weistroffer (CEA).
  • PhD in​​​‌ progress (beginning Jan. 2024):​ Théo Gérard, A multimodal​‌ Deep-Learning approach for intuitive​​ editing of character animations,​​​‌ with Marc Christie and​ Pierre Hellier (Combo team).​‌
  • PhD in progress (beginning​​ Oct. 2025): Kilian Marcelin,​​​‌ Immersive Simulation of Dense​ Crowds with Julien Pettré​‌ and Ludovic Hoyet.
  • PhD​​ in progress (beginning Nov.​​ 2025): Kebing Xue, Lighting​​​‌ estimation from images for‌ seamless integration of virtual‌​‌ objects into real scenes,​​ with Samuel Boivin and​​​‌ Marc Christie.
  • PhD in‌ progress (beginning Dec. 2025):‌​‌ Bhaswar Gupta, Data-drive crowd​​ analysis and modeling, with​​​‌ Julien Pettré.

11.2.3 Juries‌

  • Ludovic Hoyet: M. Ristorcelli‌​‌ (Nov. 2025), “Public speaking​​ training in virtual reality:​​​‌ From virtual audience simulation‌ to multimodal behavioral cues‌​‌ of performance”, Aix Marseille​​ Université, Examiner.
  • Anne-Hélène Olivier:​​​‌ Julien Lomet (PhD: Nov‌ 2025), "La collaboration dans‌​‌ une oeuvre en réalité​​ virtuelle : du processus​​​‌ de création à la‌ performativité." Université Paris VIII,‌​‌ France - Reviewer.
  • Anne-Hélène​​ Olivier: Alice Bourdon (PhD:​​​‌ Sept 2025), "Promouvoir l’activité‌ physique par l’indiçage auditif‌​‌ : vers une approche​​ personnalisée du rythme", Université​​​‌ de Montpellier, France -‌ Reviewer
  • Anne-Hélène Olivier: Charlotte‌​‌ Croucher (PhD: Jan 2025),​​ "Exploration in Virtual Reality:​​​‌ Thematic Analysis of the‌ Natural Walking Literature and‌​‌ Examination of Virtual Environment​​ Design" Tilburg University, The​​​‌ Netherlands, Reviewer.
  • Katja Zibrek:‌ Tomáš Nováček (PhD: Sept‌​‌ 2025), "Precise Hand Tracking​​ Using Multiple Optical Sensors",​​​‌ Faculty of Information Technology,‌ Czech Technical University in‌​‌ Prague, Czech Republic, Examiner.​​
  • Katja Zibrek: Celia Kessassi​​​‌ (PhD: Feb 2025), "Modelling‌ the Induction of Social‌​‌ Stress in Immersive Virtual​​ Reality Simulations", IMT Atlantique,​​​‌ Nantes, France, Reviewer.

11.3‌ Popularization

11.3.1 Productions (articles,‌​‌ videos, podcasts, serious games,​​ ...)

Ludovic Hoyet's research​​​‌ was highlighted on the‌ Esprit Sorcier video channel‌​‌ : Mouvements Personnalisés pour​​ les Foules, Esprit Sorcier​​​‌ TV, 2025. link

Julien‌ Pettré and Anne-Hélène Olivier‌​‌ particiated to the writing​​ of: Glossary for Research​​​‌ on Human Crowd Dynamics‌ 25 that appeared in‌​‌ the Collective Dynamics collection.​​

12 Scientific production

12.1​​​‌ Major publications

12.2​​​‌ Publications of the year‌

International journals

International peer-reviewed​ conferences

Scientific​​​‌ books

  • 19 bookM.‌Marc Christie, J.-B.‌​‌Jean-Baptiste Massuet and G.​​Grégory Wallet, eds.​​​‌ De l'immersion au cinéma‌.PUR-CinémaPresses Universitaires‌​‌ de RennesMay 2025​​HALback to text​​​‌

Other scientific publications

Scientific popularization

  • 25​ articleJ.Juliane Adrian​‌, M.Martyn Amos​​, C.Cécile Appert-Rolland​​​‌, M.Mitra Baratchi​, N.Nikolai Bode​‌, M.Maik Boltes​​, T.Thomas Chatagnon​​​‌, M.Mohcine Chraibi​, A.Alessandro Corbetta​‌, A.Arturo Cuesta​​, G.Guillaume Dezecache​​​‌, J.John Drury​, I.Iñaki Echeverría-Huarte​‌, S.Sina Feldmann​​, C.Claudio Feliciani​​​‌, L.Lazaros Filippidis​, Z.-J.Zhi-Jian Fu​‌, P.Paul Geoerg​​, R.Roland Geraerts​​​‌, R.Rhea Haddad​, M.Milad Haghani​‌, G.Gesine Hofinger​​, N.Nick Hopkins​​​‌, P.Pavel Hrabák​, A.Aoife Hunt​‌, X.Xiaolu Jia​​, M.Max Kinateder​​​‌, A.Angelika Kneidl​, K.Krisztina Konya​‌, G.Gerta Köster​​, L.Laura Künzer​​​‌, M.Mira Küpper​, P.Peter Lawrence​‌, R.Ruggiero Lovreglio​​, J.Jian Ma​​​‌, F.Fergus Neville​, A.Alexandre Nicolas​‌, K.Katsuhiro Nishinari​​, E.Evangelos Ntontis​​​‌, A.-H.Anne-Hélène Olivier​, D.Daniel Parisi​‌, J.Julien Pettré​​, T.Tom Postmes​​​‌, K.Kalaga Ramachandra​ Rao, E.Enrico​‌ Ronchi, A.Andreas​​ Schadschneider, J.Jette​​​‌ Schumann, S.Sebastián​ Seriani, A.Armin​‌ Seyfried, A.Anna​​ Sieben, M.Michael​​​‌ Spearpoint, G. B.​Gavin Brent Sullivan,​‌ A.Anne Templeton,​​ P.Peter Thompson,​​​‌ A.Akiyasu Tomoeda,​ A.Antoine Tordeux,​‌ C.Claudia Totzeck,​​ E.Ezel Üsten,​​​‌ N.Natalie van der​ Wal, A.Ashish​‌ Verma, N.Nanda​​ Wijermans, Z.Zeynep​​​‌ Yücel, F.Francesco​ Zanlungo, J.Jun​‌ Zhang and I.Iker​​ Zuriguel. Glossary for​​​‌ Research on Human Crowd​ Dynamics - 2nd Edition​‌.Collective Dynamics10​​May 2025, 1-32​​​‌HALDOIback to​ text