Ronan Gaugne

Virtual reality tools for the west digital conservatory of archaeological heritage

In the continuation of the 3D data production work made by the WDCAH, the use of virtual reality tools allows archaeologists to carry out analysis and understanding research about their sites. In this paper, we focus on the virtual reality services proposed to archaeologists in the WDCAH, through the example of two archaeological sites, the Temple de Mars in Corseul and the Cairn of Carn Island.

An immersive virtual sailing on the 18th-century ship le boullongne

The work presented in this article is the result of collaboration between historians and computer scientists whose goal was the digital reconstitution of Le Boullongne, an 18th-century merchant ship of La Compagnie des Indes orientales.1 This ship has now disappeared and its reconstitution aims at understanding onboard living conditions. Three distinct research laboratories have participated in this project so far. The first, a department of naval history, worked on historical documents, especially the logbooks describing all traveling events of the ship. The second, a research laboratory in archaeology, archaeoscience, and history, proposed a 3D model of the ship based on the original naval architectural plans. The third, a computer science research laboratory, implemented a simulation of the ship sailing in virtual reality.

Audio-visual attractors for capturing attention to the screens when walking in CAVE systems

In four-sided CAVE-like VR systems, the absence of the rear wall has been shown to decrease the level of immersion and can introduce breaks in presence. With this experiment we analyse how user attention is diverted while physically walking in a virtual environment, when audio and/or visual attractors are present. Key features of the experiment are the fact that auditory feedback was delivered through binaural audio rendering dependent on the users head position and orientation and that the four-sided CAVE used for the experiment allowed users to walk up to 9m in straight line. In the experiment we analysed how different “attractors” (audio and/or visual, static or dynamic) modify the users attention. Results of the experiment show that audio-visual attractors are the most efficient attractors in order to keep the users attention toward the inside of the CAVE.

Touching and interacting with inaccessible cultural heritage

The sense of touch provides a particular access to our environment, enabling a tangible relation with it. In the particular case of cultural heritage, touching the past, apart from being a universal dream, can provide essential information to analyze, understand, or restore artifacts. However, archaeological objects cannot always offer tangible access, either because they have been destroyed or are too damaged, or because they are part of a larger assembly. In other cases, it is the context of use that has become inaccessible, as it is related to an outdated activity. We propose a workflow based on a combination of computed tomography, 3D images, and 3D printing to provide concrete access to cultural heritage, and we illustrate this workflow in different contexts of inaccessibility. These technologies are already used in cultural heritage, but seldom combined, and are most often employed for exceptional artifacts. We propose to combine these technologies in case studies corresponding to relevant archaeological situations.

Preservative Approach to Study Encased Archaeological Artefacts

We propose a workflow based on a combination of computed tomography, 3D images and 3D printing to analyse different archaeological material dating from the Iron Age, a weight axis, a helical piece, and a fibula. This workflow enables a preservative analysis of the artefacts that are unreachable because encased either in stone, corrosion or ashes. Computed tomography images together with 3D printing provide a rich toolbox for archaeologist work allowing to access a tangible representation of hidden artefacts. These technologies are combined in an efficient, affordable and accurate workflow compatible with Preventive archaeology constraints.

Combination of 3D Scanning, Modeling and Analyzing Methods around the Castle of Coatfrec Reconstitution

The castle of Coatfrec is a medieval castle in Brittany constituting merely a few remaining ruins currently in the process of restoration. Beyond its great archeological interest, it has become, over the course of the last few years, the subject of experimentation in digital archeology. Methods of 3D scanning were implored in order to gauge comparisons between the remaining structures and their absent hypothetical ones, resulting in the first quantitative results of its kind. This paper seeks to introduce the methods which carried out said research, as well as to present the subsequent results obtained using these new digital tools.

Large-scale immersive reconstitution of a Neolithic corbel dome

We propose a workflow of tools and procedures to reconstruct an existing archaeological site as a virtual 3D reconstitution in a large scale immersive system. This interdisciplinary endeavor, gathering archaeologists and virtual reality computer scientists, is the first step of a joint research project with three objectives: (i) propose a common workflow to reconstruct archaeological sites as 3D models in fully immersive systems, (ii) provide archaeologists with tools and interaction metaphors to exploit immersive reconstitutions, and (iii) develop the use and access of immersive systems to archaeologists. In this context, we present results from the immersive reconstitution of Carns monument central chamber, in Finistere, France, a site currently studied by the Creaah archaeology laboratory. The results rely on a detailed workflow we propose, which uses efficient solutions to enable archaeologists to work with immersive systems. In particular, we proposed a procedure to model the central chamber of the Carn monument, and compare several softwares to deploy it in an imersive structure. We then proposed two immersive implementations of the central chamber, with simple interaction tools, and finally describe the European project Visionair which provides access to high level visualization facilities.

Photogrammetry Based Study of Ceramics Fragments

Reconstitution of whole ceramics from fragments is a true priesthood for ceramographers. This activity remains mainly handled by manual sketching and can be very time consuming. However, more and more tools and workflows provide digital solutions, based on 3D technologies, to assist such tasks. In this paper, we present an application of photogrammetry on ceramic fragments from two excavation sites located in Brittany, France. This study was required by two ceramics specialists and conducted in CReAAH, a French research center in archaeology, archaeosciences and history. The 3D restitution by photogrammetry of these different fragments allowed reconstructions of the original shapes of the potteries or at least to get to as close as possible. We furthermore used the resulting 3D models of the ceramics to compute various metrics required by the ceramographers. In collaboration with IRISA, a French research center in computer science, we designed and generated a presentation support using a 3D printer. This ...

Design and evaluation of Binaural auditory rendering for CAVEs

We describe an experiment whose goal is to investigate the usage of different audio rendering techniques delivered through headphones while walking inside a wide four-side CAVE environment. In our experiment, participants had to physically walked along a virtual path exposed to different auditory stimuli. Each subject was exposed to three conditions: Stereo, Binaural sound spatially congruent with visual and binaural sound spatially incongruent with visuals and had to rate subjectively each. The results of the experiment showed increased preference ratings for the binaural audio rendering, followed by stereo rendering. As expected incongruent spatial cues were ranked significantly lower. Binaural rendering can deliver an increased immersive experience and do no require specialized hardware.

A static analysis for program understanding and debugging

The paper presents a static pointer analysis technique for a subset of C. The tool supports user-defined assertions inserted in the body of the program. Assertions are of two kinds: static assertions automatically verified by the analyser, and hypothetical assertions treated as assumptions by the analyser. The technique deals with recursive data structures and it is accurate enough to handle circular structures.