Search

In the formal analysis of historical architecture, different geometries could be distinguished, from simple (walls, beams, columns, slabs, etc.) to more complex ones which could hardly be modelled through regular geometries (predominantly sculptural character). There are some complex geometry elements which could be processed anyway by means of mathematical models. Some forms are then often recurrent, apparently different, but associated to common matrices, which could be therefore parameterized. In these cases the survey does not concern the form in its complexity, but only the parametric elements, then creating the needed relationship between the variable parameters in the Building Information Model and other models derived from point cloud. On this topic a first experiment was made in the survey of the “Scala Regia” in the Vatican.

The paper illustrates the results of a research on integrated digital survey of the "Fontana Rustica" in the gardens of the Quirinale, artifact somewhat atypical for its particular organical configuration, and whose history is still to be discovered. The activity is performed by Critevat, interdepartmental research center in Rieti, within of the scientific collaboration with the Office for the conservation of artistic heritage of the Quirinale Palace. The integrated digital survey in recent years has had a strong impulse thanks to the technological development of the shape acquisition instruments. The research has analyzed the problems of interaction and integration of digital data obtainable using the latest digital technologies such as 3D laser-scanner and digital photogrammetry. A further level of research has focused on the possibility of management of 3D models in relation to data obtained by instruments and methods of investigation of different scientific culture such as seismic transmission tomography and thermografy.

Some recent personal studies on the most representative helicoidal staircases of the Renaissance and Baroque were an opportunity to compare two emblematic figures of the ’500 Italian, Vignola and Mascarino. The first is known to all, the second is certainly less well known though new historical studies are re-evaluating his work also as architect. This paper aims to demonstrate how a careful reading and interpretation of two of their works, particularly significant on the same theme, allows to focus with great evidence the project control skills through application of the principles of geometry and their care and attention during the realization, always thanks to their geometrical expertise. The study finally made it possible to shed new light on the real contribution of Ottaviano Mascarino in the late Renaissance architecture, anticipating a few decades some formal innovations of the Roman Baroque.

The paper concerns the study of the shape and geometry of the helicoidal staircase in Barberini Palace. Integrated models of representation (graphic and 3D) have been produced starting from the digital data acquired by a laser scanner, processed and subsequently managed through procedures for optimizing the cloud-points.The realization of the helicoidal staircase in the Barberini Palace has an important rule in the architectural history because it is a wonderful example of the constructive development of a complex geometric shape which is a helix oval. This stair should be read and interpreted as evidence of a particular period,the Roman Baroque, rich of intertwining and overlapping of ecclesiastical and noble commissions, of alternations in the yards of the greatest artists and architects of the era, often working simultaneously. Borromini proposes a modification to the first design of Maderno, which included a helicoidal staircase to the right of the large porch entrance to the palace, imagining a new oval stair with a set of six twin columns for each revolution, very similar to the staircase that had been built a few years earlier, in 1585, at the Quirinale Palace by the Mascherino. Borromini had worked a few years earlier, under the direction of Maderno, in the Quirinal Palace, having a possibility to carefully study the Mascherino’s oval stair .Following the death of Maderno (1629) the yard of the Barberini Palace takes over the Bernini. Borromini will initiate a collaboration destined to end soon. The scale will be built in 1633 when now Borromini had already left the yard.The article wants above all to highlight the correlations between form and geometry when designing a campaign of digital acquisition using a laser scanner. Indeed, there are important implications to choice the positioning points of the instrument, with important fallout on the relationship between quality and quantity of a points cloud. The points cloud is a 3D model, first of all measurable, but also able to disclosing shapes and geometries otherwise hardly perceptible, selecting parts or showing details.A first reading level of the models, obtained according to consolidated procedures of the points-cloud management, has highlighted the formal matrix of the oval with the identification of the centers of the polycentric line, the resulting three-dimensional development of the various helices belonging to cylindrical surface portions adjacent to each other and different radius, the relationship with the slope. Within this formal matrix of the first level it enters the formal matrix of the architectural order into the rhythm of the six pairs of alternate columns and of the balustrades, and in the entablature that develops as a tape into the central space illuminated by a skylight.The modular structure of the scale has also suggested a experimentation by means of parametric modeling techniques to try to trace the ideal model of the Borromini’s helical staircase. The digital parametric model tested here is a new mode of representation than the models already consolidated, either analog or digital. Through a critical selection of some remarkable points belonging to the geometries present, through a statistical and normalized observation of the recurring measures, we have identified a generative algorithm able to be representative of the design intentions of the author. The entire search path followed to reach the definition of parametric generative model – from analysis of the real model to the design of the virtual parametric model; from the development of the algorithm generative until to his check made by comparing the generated model and the model survey - it was found to be a constraint rigorous methodological for a more complete and appropriate knowledge of the work.

Photogrammetry, the scientific discipline through which detect the spatial properties and form of an object from one or more photographs, hasundergone many transformations. The use in the title of the dot notation, coined by Tim O’Reilly in 2004 related to the evolution of the web, wantsto emphasize the scope of this transformation. A new concept of metric correlation has developed through which we can obtain three-dimensionalinformation of an object using any camera. Photographic images can also be easily manipulated so as to create the most disparate projective relationships, unimaginable until a few decades ago. The paper aims to point out the changes induced in the transition from analytical to digital and the role of the new photogrammetry in the integrated digital survey considering some aspects of integration and interrelation with other innovative instrumental techniques of survey.

Among the several information available on web the spherical panoramas by Google can be an important reference for the 3D models elaboration of urban contexts and historic buildings, difficult to access or even destroyed as a result of wars or natural disasters. Starting from the spherical photogrammetry, thoroughly tested and used by some scholars, the goal of this research was to verify the reliability in the use of spherical panoramas by Google in the architectural and urban survey, considered that in some cases such as in the recent earthquake that hit central Italy, these images represent the only “visual” evidence of something that no longer exists.

Il saggio tratta il tema della linea curva nei disegni di Francesco Borromini mettendo in evidenza come, in essi, una sequenza di linee riesca a determinare una geometria complessa. L’analisi è condotta sul disegno AzRom 108, pianta del tiburio di Sant’Andrea delle Fratte, a Roma, la cui costruzione avvenne tra il 1652 e il 1665. L’analisi delle curve disegnate mette in evidenza come il tiburio prenda forma attraverso una sequenza di linee appartenenti a piani orizzontali sovrapposti, all’interno di una costruzione geometrica pensata nello spazio, ma che le governa tutte su di un unico piano. Borromini traccia, quindi, una pianta sinottica, costruendo nelle due dimensioni un ragionamento tridimensionale. La pianta, tralasciando il disegno parziale ad essa sovrapposto, riferibile ad una lanterna prevista e non realizzata, descrive la quota di sezione che taglia le quattro finestre, evidenziandola con un tratteggio inclinato, ma rappresenta con un segno continuo anche la proiezione della cornice sopra le colonne e quella più esterna di coronamento. Non compare invece, in questo disegno, il basamento che ha, sui quattro lati, compreso tra gli speroni angolari, un andamento concavo-convesso continuo, sul tipo di quello che modella la parte inferiore della facciata del San Carlino. All’analisi delle curve disegnate segue, quindi, un ragionamento sulle curve effettivamente realizzate, desunte dal modello tridimensionale ricavato dal rilievo 3D, e la verifica della relazione tra la curva sinusoidale del basamento e la linea spezzata del dado impostato sui piloni di crociera. Chiudono il saggio alcune considerazioni sulla continuità figurativa che, nell’opera di Borromini, lega le parti costitutive del tutto agli elementi di dettaglio. Egli, infatti, attribuisce alla linea, entità geometrica per definizione unidimensionale, lo stesso valore formale, sia che essa ritagli lo spazio minuto di una sequenza di modanature, sia che modelli l’interno o l’esterno di un invaso architettonico. In this essay we examine the theme of the curved line in Francesco Borromini’s drawings, highlighting how a sequence of lines manages to determine a complex geometry. We analyzed the drawing AzRom 108, plan of the tiburium of Sant’Andrea delle Fratte, in Rome, constructed between 1652 and 1665. The analysis of the curves shows how the tiburium takes shape via a sequence of lines lying on overlapping horizontal planes, within a geometric construction conceived in space, but which governs them all onto a single plane. Borromini then traces a synoptic plan, thus creating three-dimensional reasoning within two dimensions. The drawing, omitting the overlapping partial drawing referring to a lantern that had been envisaged but not realized, describes the plan elevation cutting through the four windows, evidenced with slanted hatching, also representing the projection of the cornice over the columns and the outer cornice with a continuous line. However, in this drawing the base with its continuous concave-convex profile on the four sides within the corner contraforts – of the type that forms the lower part of the San Carlino façade is not shown. The analysis of the drawn curves, therefore, is followed by a reasoning on those curves actually realized, derived from the three-dimensional model obtained with the 3D survey, and the verification of the relationship between the sinusoidal curve of the base and the ragged line of the dado stacked above the pylons of the crossing. The essay concludes with considerations on the figurative continuity which, in Borromini’s work, binds the constituent parts of the whole to the elements of detail. In fact, he attributes the same formal value to the line, a one-dimensional geometric entity by definition, whether it carves out the minute space in a sequence of moldings or models the interior or exterior of an architectural enclosure