Livio De Luca

Semantic 3D Media and Content: A semantic-based platform for the digital analysis of architectural heritage

This essay focuses on the fields of architectural documentation and digital representation. We present a research paper concerning the development of an information system at the scale of architecture, taking into account the relationships that can be established between the representation of buildings (shape, dimension, state of conservation, hypothetical restitution) and heterogeneous information about various fields (such as the technical, the documentary or still the historical one). The proposed approach aims to organize multiple representations (and associated information) around a semantic description model with the goal of defining a system for the multi-field analysis of buildings.

Reverse engineering of architectural buildings based on a hybrid modeling approach

This article presents a set of theoretical reflections and technical demonstrations that constitute a new methodological base for the architectural surveying and representation using computer graphics techniques. The problem we treated relates to three distinct concerns: the surveying of architectural objects, the construction and the semantic enrichment of their geometrical models, and their handling for the extraction of dimensional information. A hybrid approach to 3D reconstruction is described. This new approach combines range-based modeling and image-based modeling techniques; it integrates the concept of architectural feature-based modeling. To develop this concept set up a first process of extraction and formalization of architectural knowledge based on the analysis of architectural treaties is carried on. Then, the identified features are used to produce a template shape library. Finally the problem of the overall model structure and organization is addressed.

A generic formalism for the semantic modeling and representation of architectural elements

This article presents a methodological approach to the semantic description of architectural elements based both on theoretical reflections and research experiences. To develop this approach, a first process of extraction and formalization of architectural knowledge on the basis of the analysis of architectural treaties is proposed. Then, the identified features are used to produce a template shape library dedicated to buildings surveying. Finally, the problem of the overall model structuring and organization using semantic information is addressed for user handling purposes.

Application of digital techniques in monument preservation

Health records for monuments are produced to provide a basis for scientific monitoring and planning of restoration work. The collected data (locations of deterioration, and architectural and historical archives) must be referenced in a single documentation platform to establish a detailed diagnosis of the state of degradation of the monument. This paper presents the application of digital techniques for production of a health record of a monument, applied to the castle of Chambord (Loire Valley, France). The first step is to provide a 3D digital reconstruction of the monument. This 3D modelling consists in constructing a finely refined and relevant graphic base to spatially reference all data acquired during the project. Topography is used to precisely locate the relative position of the main architectural components, while photogrammetry can set in detail each of these elements. The application of textures extracted from pictures on surfaces of the 3D model provides a realistic appearance. Additional data from a laser scanner can be included to detail complex forms or specific degraded areas for monitoring or documentation purpose. The state of deterioration of the structure is evaluated through a visual in situ survey. Dating and identification of rocks are determined by searching in the historical and architectural archives that are sometimes incomplete. Finally, the NUBES web-based platform is used to spatially associate data with the 3D model of the monument. This database underpins the health record of the castle of Chambord.

An Iconography-Based Modeling Approach for the Spatio-Temporal Analysis of Architectural Heritage

The study of historic buildings is usually based on the collection and analysis of iconographic sources such as photographs, drawings, engravings, paintings or sketches. This paper describes a methodological approach to make use of the existing iconographic corpus for the analysis and the 3D management of building transformations. Iconography is used for different goals. Firstly, its a source of geometric information (image-based-modeling of anterior states); secondly, its used for the re-creation of visual appearance (image-based texture extraction); thirdly its a proof of the temporal distribution of shape transformations(spatio-temporal modeling); finally it becomes a visual support for the study of building transformations (visual comparison between different temporal states). The aim is to establish a relation between the iconography used for the hypothetical reconstruction and the 3D representation that depends on it. This approach relates to the idea of using 3D representations like visualization systems capable of reflecting the amount of knowledge developed by the study of a historic building.

Protocols and assisted tools for effective image-based modeling of architectural elements

Domains related to documentation, conservation, restoration and enhancement of heritage objects use more and more digital 3D surveying. Image-based methods, due to their low-cost and accessibility, constitute an interesting alternative to traditional laser scanning surveys. However, these tools, often based on computer vision methods, are either difficult to use or not sufficiently accurate for scientific purposes. Within this context, this paper presents a photogrammetric pipeline in order to prove every heritage agent with a suitable and efficient solution for digitizing architectural and archaeological elements, taking into account the entire process, from the acquisition to the 3D result.

UAV photogrammetry for archaeological survey: The Theaters area of Pompeii

Aerial surveying is, in the domain of archeology and architecture, an exponential field of application and interest. Beyond the increasing flying capabilities and skills of existing UAV, the operational potentiality of the aircraft oversteps the imagination of their own creators. Initially conceived for robotic civilian and military surveying applications, recent experiments have tested autonomous flight, self decision-making and multi-agent convergent tasks. Based upon 10 years of aerial surveying experience, part of the MAP activity is concerned: firstly, unmanned flight and related developments within a specific institutional partnership and secondly, advanced tool-making workflow for architecture and urban design 3D modeling and image analysis protocols. In this paper we will describe a particular operational pipeline tested on the Theaters Area of Pompeii in Italy, starting from aerial data collection to accurate 3D processing with the help of innovative co-operative technologies.

An Interactive 3-Dimensional Database Applied to the Conservation of a Painted Chapel

Matteo Giovannettis frescoes (1355-1356) which decorate the Innocent VI chapel of La Chartreuse du Val des Benedictins (Villeneuve-lez-Avignon, France) are very sensitive to the alteration. They need a new restoration campaign. Because of the geometrical complexity of the place, the environment and the involved degradation mechanisms, a good conservation management of these murals is essential. Therefore, an interactive 3- dimensional spatial database, including dated data was developped. Architectural measurements, digital scientific documentation were gathered. A historical documentation including restoration acts, used restoration products has been collected. Last, the paintings degradations, up-to-date deterioration patterns description and conservation state diagnosis of these wall paintings including a deterioration mapping are monitored. Results of the physical and chemical analyses of painting, restoration techniques and deterioration products are also integrated. The entire collected and interac...

Documentation and Analysis of 3D Mappings for Monument Diagnosys

The restoration and preservation of built cultural heritage requires a good knowledge of its history and its current state of conservation. Heritage con-servation professionals are used to perform mappings to record and disseminate data relative to the monument. Data to be collected are heterogeneous, starting from the oldest sources (such as archives or iconographic manuscript) up to field observations. This study is applied to the documentation and analysis of the state of conservation of the East tower in the castle of Chambord. The produced map-pings concern the dating of stonework, the nature and origin of each stone, and the distribution of degradation patterns on the outer walls. To enable the graphical drawing and viewing of the different mappings, it is necessary to produce a suitable digital medium. In this study, the medium is a textured 3D model as a mean to characterize accurately and actually all surfaces, including those that cannot be viewed on a 2D projection. This 3D model is associated to the NUBES database to store and analyse all collected data. NUBES is a web-based open source platform for the representation, documentation and analysis of architectural elements. This information system has been specifically developed to include an interface dedicated to the drawing vector mappings and to their organization into hierarchical layers. Results of this study can be used to improve the monument diagnosis and our knowledge of weathering processes.

3D information system for the digital documentation and the monitoring of stone alteration

Today mapping of alterations of cultural heritage buildings and estimation of their degradation patterns is still a difficult task for several reasons. On one hand, buildings suffer from degradation problems depending on physical and chemical factors, whose causes can be difficult to determine. On the other hand, at the level of data representation, graphic supports need to be defined for deterioration analysis and heterogeneous data manipulation. The goal of this research is to supply experts with a tool for scientific monitoring and decision support so to permit rational programming operations of restorations. This paper proposes an approach for digital documentation of conservation state of buildings (stone alteration, dating, material), permitting to display and cross-reference data related to degradations. This approach will be described through the study case of stones at Chambord Castle.