Realtime projective multi-texturing of pointclouds and meshes for a realistic street-view web navigation

International audienceStreet-view web applications have now gained widespread popularity. Targeting the general public, they offer ease of use, but while they allow efficient navigation from a pedestrian level, the immersive quality of such renderings is still low. The user is usually stuck at specific positions and transitions bring out artefacts, in particular parallax and aliasing. We propose a method to enhance the realism of street view navigation systems using a hybrid rendering based on realtime projective texturing on meshes and pointclouds with occlusion handling, requiring extremely minimized pre-processing steps allowing fast data update, progressive streaming (mesh-based approximation, with point cloud details) and unaltered raw data precise visualization

Underground Visualization: web-app, virtual reality, ex situ and in situ augmented reality.

International audienceIn this work-in-progress and demo paper, we present an ongoing experiment of underground visualization, in the context of urban 3D geovisualization, for operational purposes in urban planning. After a preliminary project of sewers network digitization (Nguyen et al., 2018), the 3D model of sewers has been made available for web visualization and interaction. In this paper, we show that it is possible to address various use contexts, when adding the ability to visualize and interact with the sewer 3D model in virtual reality (VR) and in ex situ / in situ augmented reality (AR). These experiments will be further experimented to validate our hypotheses to favor collaboration, immersion for simulation and training, and more secured urban development

Rendu basé image de fonds photographiques historiques massifs

This paper states an overview of my dissertation research centered on the continuous immersive visualization and navigation through time and space of large sets of historical photographs. The research aims for: (i) the treatment of scientific obstacles (e.g. data volume, heterogeneity, distortions, and uncertainties) that appear when old pictures are placed in today's environment; (ii) the visualization (saliently and spatially) of these photos. The main model of the study is image-based rendering IBR, because of its capacity to use imprecise or non-existent geometry (i.e. since a modern 3D scene may differ from a historical one, due to environmental changes over time). The findings of this work may contribute significantly by extending the current IBR models and providing a new innovative way to examine these massive and heterogeneous datasets.Cet article donne un aperçu de ma thèse de doctorat centrée sur la visualisation immersive continue et la navigation dans le temps et dans l’espace de grands ensembles de photographies historiques. Les objectifs de la recherche sont les suivants: (i) traitement des obstacles scientifiques (volume de données, hétérogénéité, distorsions et incertitudes, par exemple) qui apparaissent lorsque de vieilles images sont placées dans l’environnement actuel; (ii) la visualisation (de manière saillante et spatiale) de ces photos. Le modèle principal de l’étude est le rendu IBR basé sur l’image, en raison de sa capacité à utiliser une géométrie imprécise ou inexistante (c’est-à-dire qu’une scène 3D moderne peut différer de l’historique, en raison des changements environnementaux survenus au fil du temps). Les résultats de ce travail pourraient contribuer de manière significative en étendant les modèles IBR actuels et en fournissant un nouveau moyen innovant d’examiner ces ensembles de données massifs et hétérogènes

INTERACTIVE IMAGE GEOLOCALIZATION IN AN IMMERSIVE WEB APPLICATION

For a long time people have been interested in the past and history and how we can go back in time using a time machine. And while we cannot invent a time machine, at least not yet, we can create a virtual one. Our “virtual” time machine is an interactive web application that allows users to browse through and navigate within historical images (aerial/terrestrial photographs or postcards) that are projected on a 3D photogrammetric model (point cloud or 3D mesh), thus going back in time and interacting with historical 3D models and images. This was achieved by adopting a semiautomatic approach where the user identifies first 6 to 8 hints on the historical image and the photogrammetric model, then this information is used as an entry data to a photogrammetric software that computes the pose and orientation of the image. The purpose of this work, which is part of the ALEGORIA project, is to preserve cultural heritage, to give the users the opportunity to go back in time and study history of a place or simply discover how their hometown looked some years ago

3D URBAN GEOVISUALIZATION: IN SITU AUGMENTED AND MIXED REALITY EXPERIMENTS

In this paper, we assume that augmented reality (AR) and mixed reality (MR) are relevant contexts for 3D urban geovisualization, especially in order to support the design of the urban spaces. We propose to design an in situ MR application, that could be helpful for urban designers, providing tools to interactively remove or replace buildings in situ. This use case requires advances regarding existing geovisualization methods. We highlight the need to adapt and extend existing 3D geovisualization pipelines, in order to adjust the specific requirements for AR/MR applications, in particular for data rendering and interaction. In order to reach this goal, we focus on and implement four elementary in situ and ex situ AR/MR experiments: each type of these AR/MR experiments helps to consider and specify a specific subproblem, i.e. scale modification, pose estimation, matching between scene and urban project realism, and the mix of real and virtual elements through portals, while proposing occlusion handling, rendering and interaction techniques to solve them