El Modelo Analítico Tridimensional obtenido por fotogrametría. Descomposición, manipulación y aplicaciones en el campo de la restauración arquitectónica

Abstract

Historic buildings present a deformed and eroded shape and geometry which increases the three-dimensional complexity of their structure. Analytical photogrammetry and its register in CAD programmes make it possible to draw complete analytical 3D models of the buildings. These represent all of the visible surfaces in a single drawing in a unique coordinates system, which makes it possible to place each line in its real spatial position. These models of lines are transparent, which prevents background lines from being hidden, and use a great deal of memory, which hinders their IT use. To resolve this problem it is necessary to break down the 3D model into files and drawing layers. Each drawing file includes the restored lines of a constructive element and is identified by the typology of the element and its position in the space of the building. The lines are separated into layers according to their geographic orientation and typology (arris, contour, fissure, etc.) The administration of the set of files making up the 3D model is carried out directly by designation or graphically via a simplified guide map in which each line pertains to a file. The 3D analytic model is an IT model of the monument that permits us metric, geometric constructive and structural visualizations and analyses which would be impossible without this tool. By connecting through information technology each of these drawn entities with an external system of databases of studies of the monument, it will be possible to establish what we know as a «Monument Information System» or MIS.