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Pierre Raimbaud

Publications and source records attributed to Pierre Raimbaud.

4 recordsLinked to original sources

Dynamic Thermal Feedback in Highly Immersive VR Scenarios: a Multimodal Analysis of User Experience

Thermal feedback is critical to a range of Virtual Reality (VR) applications, such as firefighting training or thermal comfort simulation. Previous studies showed that adding congruent thermal feedback positively influences User eXperience (UX). However, existing work did not compare different levels of thermal feedback quality and mostly used less immersive virtual environments. To investigate these gaps in the scientific literature, we conducted a within-participant user study in two highly-immersive scenarios, Desert Island (n=25) and Snowy Mountains (n=24). Participants explored the scenarios in three conditions (Audio-Visual only, Static-Thermal Feedback, and Dynamic-Thermal Feedback). To assess the complex and subtle effects of thermal feedback on UX, we performed a multimodal analysis by crossing data from questionnaires, semi-structured interviews, and behavioral indicators. Our results show that despite an already high level of presence in the Audio-Visual only condition, adding thermal feedback increased presence further. Comparison between levels of thermal feedback quality showed no significant difference in UX questionnaires, however this result is nuanced according to participant profiles and interviews. Furthermore, we show that although the order of passage did not influence UX directly, it influenced user behavior. We propose guidelines for the use of thermal feedback in VR, and the design of studies in complex multisensory scenarios.

cs.HC

Kineo: Calibration-Free Metric Motion Capture From Sparse RGB Cameras

Markerless multiview motion capture is often constrained by the need for precise camera calibration, limiting accessibility for non-experts and in-the-wild captures. Existing calibration-free approaches mitigate this requirement but suffer from high computational cost and reduced reconstruction accuracy. We present Kineo, a fully automatic, calibration-free pipeline for markerless motion capture from videos captured by unsynchronized, uncalibrated, consumer-grade RGB cameras. Kineo leverages 2D keypoints from off-the-shelf detectors to simultaneously calibrate cameras, including Brown-Conrady distortion coefficients, and reconstruct 3D keypoints and dense scene point maps at metric scale. A confidence-driven spatio-temporal keypoint sampling strategy, combined with graph-based global optimization, ensures robust calibration at a fixed computational cost independent of sequence length. We further introduce a pairwise reprojection consensus score to quantify 3D reconstruction reliability for downstream tasks. Evaluations on EgoHumans and Human3.6M demonstrate substantial improvements over prior calibration-free methods. Compared to previous state-of-the-art approaches, Kineo reduces camera translation error by approximately 83-85%, camera angular error by 86-92%, and world mean-per-joint error (W-MPJPE) by 83-91%. Kineo is also efficient in real-world scenarios, processing multi-view sequences faster than their duration in specific configuration (e.g., 36min to process 1h20min of footage). The full pipeline and evaluation code are openly released to promote reproducibility and practical adoption at https://liris-xr.github.io/kineo/.

cs.CV

StimulHeat: a Low-Energy Wearable Thermal Feedback Device Using Peltier Elements with Heat Flow Controlled Loop for Hand Interactions in Virtual Reality

Nowadays, the majority of wearable thermal feedback systems designed for use in virtual reality applications are not compatible or not integrated to standard controllers and are based on temperature control. The objectives of the present work is to enable integration with existing controllers, in this case Valve Index controllers, and to propose an alternative approach to managing thermal stimulation with Peltier modules by controlling heat flow instead of temperature. We introduce StimulHeat as a wireless, low power thermal feedback system, based on the continuous relationship between heat and current injection in thermoelectric device (TED). First, we designed an optimized TED driver capable of injecting a continuous, bidirectional current into the TED, thereby driving it as a heater or cooler. Subsequently, this driver was implemented in an electronic board to include temperature and heat flow control loops, as well as Bluetooth Low Energy interface for remote control. A mechanical integration was conducted, in the form of a controller extension which is non-intrusive and can be clipped to Valve Index controllers to enclose the TED, temperature sensors and electronics. Finally, we present a user study validating StimulHeat for use in Virtual Reality, utilizing a Unity-built virtual environment with our open-source package.

eess.SY

Extracting and visualizing a new classification system for Colombia's National Administrative Department of Statistics. A visual analytics framework case study

In a world filled with data, it is expected for a nation to take decisions informed by data. However, countries need to first collect and publish such data in a way meaningful for both citizens and policy makers. A good thematic classification could be instrumental in helping users navigate and find the right resources on a rich data repository as the one collected by Colombia's National Administrative Department of Statistics (DANE). The Visual Analytics Framework is a methodology for conducting visual analysis developed by T. Munzner et al. [T. Munzner, Visualization Analysis and Design, A K Peters Visualization Series, 1, 2014] that could help with this task. This paper presents a case study applying such framework conducted to help the DANE better visualize their data repository, and present a more understandable classification of it. It describes three main analysis tasks identified, the proposed solutions and the collection of insights generated from them.

cs.HC