Departamento de Artes, Humanidades e Ciências Sociais

In this article we intend to discuss the potential and usability of the methods and tools of terrestrial laser scanning (TLS) and automatic digital photogrammetry (ADP) for the recording and production of base documentation as support to conservation analysis and intervention. These tools, TLS and ADP, can be very efficient, not only to the geometric and radiometric recording, but also as instrument for several types of analysis. It will be presented three case studies: i) “Convento de Cristo” in Tomar, ii) “Arco da Rua Augusta” in Lisbon, and iii) “Palácio de Valflores” in Loures. In these cases TLS and ADP were used as complementary tools to the recording of the built structure. TLS was also used as an instrument for anomalies detection, to measure deformations and gaps and to perform a comprehensive survey of the building. This information is being used to plan and implement conservation measures.

Surface reconstruction is an important issue in geometric modelling. It has received a lot of attention in the computer graphics community in recent years because of image technologies development, namely laser scanning technology, and their wide applications in areas such as reverse engineering, product design, medical devices design and archaeology, among others. In building and rehabilitation areas, laser scanning has been widely applied in the field of architecture for the survey of geometric characteristics of historic buildings. The high speed and accuracy of data acquisition allows the reconstitution of 3D models with a level of detail and precision, exceeding conventional techniques. With this work, it is intended to visualize data acquired from 3D laser scanning and develop a crack characterization and modelling algorithm. This study is developed and implemented using Mathematica algebraic and symbolic platform tools, and in a final stage the opensource application Meshlab is used for the global assembly visualization. Concerning the methodology used, the first approach is the development of automatic extraction of several non-disjoint points process, corresponding to a surface portion. After this, two types of filters are used: the first to eliminate redundant points and thus providing a more efficient cloud, the other to detect crack points.
Mathematica allowed us to visualize the interpolations surface of the points sample and obtain an approximation of the surface reconstruction.

This paper describes a generative design approach integrating real building data in the process of developing a shape grammar. The goal is to assess to which extent it is feasible the use of a reverse engineering procedure to acquire actual building data and what kind of impact it may have on the development of a shape grammar.
The paper describes the use of Terrestrial Laser Scanning (TLS) techniques to acquire information on the São Vicente de Fora church, then the use of such information to develop the corresponding shape grammar, and finally the comparison of this grammar with the grammar of Alberti’s treatise, to determine the grammatical transformations that occurred between the two grammars.

In this paper we describe an experience undertaken in the Faculty of Architecture of Technical University of Lisbon, concerning the introduction of a 3D Digitization course in the frame of the PhD doctorate program in Architecture and in the frame of the Master’s programs in Architecture, Urbanism and Design.
We start by describing the theoretical and instrumental frameworks proposed. Then we describe and discuss a set of two exercises developed during one semester, giving examples of the work produced by the students. Finally we end with some considerations to be taken into account in future editions of the course.

The objectives of this paper are to demonstrate that image based three dimensional reconstruction techniques, such as structure from motion (SFM) and multi-view-stereo (MVS) enable the production of documentation with comparable quality to the one produced with terrestrial laser scanning (TLS). We start by demonstrating that proposition and then, will present two more case studies where those techniques were used to produce data for the archaeological recording. In one of those, SFM/MVS was combined with TLS, providing a new layer of information after excavation was done.

Over the last few decades photogrammetry and laser
scanning have been frequently considered valuable tools for
creating three-dimensional models from which metric and
radiometric information can be derived for the survey of cultural heritage buildings, reverse engineering, space exploration and other areas. However reconstructing old heritage buildings digitally may be a challenging task especially when the shape, geometry and volume of these buildings are intrinsically complex therefore requiring specific methods or ad-hoc solutions. Medieval castles are typical constructions that exhibit these kinds of features with inaccessible locations, bridges, wide areas followed by small and limited spaces, battlements, towers and walls occluded by vegetation. This variety of problems can prolong the time required to complete the tasks when using laser scanning or photogrammetry with conventional lenses. In this paper we present a research of use of fisheye lenses in photogrammetry, for capturing medieval castles’ geometric and radiometric information of hard to reach places. We conclude that this reduces the total time needed to capture the same amount of information gathered with other instruments, it allows replacing the usage of Unmanned Aerial Vehicles (UAV) in low flight situations, makes the survey connection between areas of a building easier, reduces the total number of images and allows making a general fast survey. The castles illustrated in this paper are the Castle of Sesimbra and the Castle of The Convent of Christ, both in Portugal.

This paper describes the use of the visual programming interface Grasshopper, which runs in Rhinoceros software, in the development a parametric paneling solution for the design of a kiosk’s interior cladding. The specific design problem includes: i) the geometric definition of the inner surfaces of the kiosk, ii) the subdivision of the surfaces
into small components defining a stereotomic pattern, taking into account the milling fabrication technology that will be used to fabricate the pieces, and iii) laying out the numbered pieces for fabrication. Firstly, we describe the programming interface; secondly, we explain the constraints of the problem and how they were used as parameters; thirdly, we describe the parametric modeling workflow; and, fourthly, we
explain how the fabrication technology and the materials selected for the fabrication affected the conceptual strategy. Additionally, we indicate how this kind of modeling strategy can be used in other contexts, such as reverse engineering using laser scanning data as input.

The scientific session DocGraf '16 aims to be a forum for debate and discussion on the role of digital technologies in research in Architecture and Urbanism. In this first session experts from various fields of knowledge share experiences where the use of these new tools, specifically from the area of geomatics and computer graphics, proved to be a critical success factor in the projects in which have been integrated.
The session will also feature the presentation of the project Architectural Democracy that focuses on the relationship between architecture, technology and policy and its implications in the context of citizenship, architectural practice and urban policies. The line of research focuses on ways to use technology to transform buildings in "open-source" interfaces to improve citizens' understanding of the everyday built environment and, therefore, the quality of architecture and citizenship.