Deformations in a 16Th-Century Ceiling of the Pinelo Palace in Seville (Spain)

International Journal of Geo-Information

Article Digital Graphic Documentation and Architectural Heritage: Deformations in a 16th-Century Ceiling of the Pinelo Palace in Seville (Spain)

Juan Francisco Reinoso-Gordo 1,* , Antonio Gámiz-Gordo 2 and Pedro Barrero-Ortega 3

1 Architectural and Engineering Graphic Expression, University of Granada, 18071 Granada, Spain 2 Architectural Graphic Expression, University of Seville, 41012 Seville, Spain; [email protected] 3 Graphic Expression in Building Engineering, University of Seville, 41012 Seville, Spain; [email protected] * Correspondence: [email protected]; Tel.: +34-958-249-485

Abstract: Suitable graphic documentation is essential to ascertain and conserve architectural heritage. For the first time, accurate digital images are provided of a 16th-century wooden ceiling, composed of geometric interlacing patterns, in the Pinelo Palace in Seville. Today, this ceiling suffers from significant deformation. Although there are many publications on the digital documentation of architectural heritage, no graphic studies on this type of deformed ceilings have been presented. This study starts by providing data on the palace history concerning the design of geometric interlacing patterns in carpentry according to the 1633 book by López de Arenas, and on the ceiling consolidation in the 20th century. Images were then obtained using two complementary procedures: from a 3D laser scanner, which offers metric data on deformations; and from photogrammetry, which facilitates Citation: Reinoso-Gordo, J.F.; the visualisation of details. In this way, this type of heritage is documented in an innovative graphic Gámiz-Gordo, A.; Barrero-Ortega, P. approach, which is essential for its conservation and/or restoration with scientific foundations and Digital Graphic Documentation and also to disseminate a reliable digital image of the most beautiful ceiling of this Renaissance palace in Architectural Heritage: Deformations southern Europe. in a 16th-Century Ceiling of the Pinelo Palace in Seville (Spain). ISPRS Int. J. Geo-Inf. 2021, 10, 85. Keywords: ceiling; 16th century; Pinelo; palace; Seville; deformation; scanner; photogrammetry https://doi.org/10.3390/ijgi10020085

Academic Editors: Sara Gonizzi Barsanti, Mario Santana Quintero and 1. Introduction Wolfgang Kainz 1.1. Short History of the Pinelo Palace in Seville (Spain) The Renaissance palace of the Pinelo family is located in an urban framework of me- Received: 9 January 2021 dieval origin, on a corner where Abades and Segovias streets intersect, near the Cathedral Accepted: 17 February 2021 of Seville and the popular neighbourhood of Santa Cruz (Figure1a). It was built in around Published: 19 February 2021 1500 by a family of prosperous merchants from Genoa who played a prominent role in the Casa de la Contratación in Seville and the commercial relationships between Spain and the Publisher’s Note: MDPI stays neutral Americas [1–3]. with regard to jurisdictional claims in In 1523, the Pinelo family sold the palace to the Cabildo Catedralicio. Nothing is published maps and institutional afﬁl- known about the subsequent transformations of the palace until it changed its usage in iations. around 1885, when it became Guest House Don Marcos [4]. In 1954 it was declared a historical-artistic monument and in 1964 it was expropriated by the Seville City Council. Between 1967 and 1971, some consolidation work was carried out by the municipal architect Jesús Gómez-Millán, and between 1969 and 1981 major restoration was directed by the Copyright: © 2021 by the authors. architect Rafael Manzano Martos [5]. Since then, the building has been the headquarters Licensee MDPI, Basel, Switzerland. of the Real Academia de Buenas Letras and the Real Academia de Bellas Artes de Santa Isabel This article is an open access article de Hungría in Seville. Inside, the building is organised into three large courtyards in distributed under the terms and accordance with the typical layout in Spanish medieval architecture [6] (Figure1b): an conditions of the Creative Commons entrance courtyard, where the stables were located; a main courtyard, with a large staircase Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ located in one corner, from which the mezzanine can be accessed where the ceiling studied 4.0/). in the present research is located; and a third courtyard/garden.

ISPRS Int. J. Geo-Inf. 2021, 10, 85. https://doi.org/10.3390/ijgi10020085 https://www.mdpi.com/journal/ijgi ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 2 of 17

ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 2 of 17 staircase located in one corner, from which the mezzanine can be accessed where the ceiling studied in the present research is located; and a third courtyard/garden. ISPRS Int. J. Geo-Inf. 2021, 10, 85 2 of 17 staircase located in one corner, from which the mezzanine can be accessed where the ceiling studied in the present research is located; and a third courtyard/garden.

(a) (b) Figure 1. (a) Modern aerial photograph of the Pinelo Palace and its surroundings (overview through Google Earth). (b) Ground floor and mezzanine (indicated by the red circle). Authors’ own drawing, 2020. (a) (b)

FigureFigure 1. 1.(a )(a Modern) Modern aerial aerial photographphotograph of of the theThe Pinelo Pinelo lookout Palace Palace tower and and its built surroundin its surroundings in thegs corner(overview (overview between through through the Google two Google Earth) exterior. ( Earth).b) façades of the Ground floor and mezzanine (indicated by the red circle). Authors’ own drawing, 2020. (b) Ground floor and mezzanine (indicatedbuilding by the would red circle). be the Authors’ first such own tower drawing, built 2020. in Seville under the influence of the villas of the Italian Renaissance. Under the lookout tower is the entrance (Figure 2a). The main TheThe lookout lookoutcourtyard tower tower constitutes built built in inthe a prime the corner corner example between between of theSevillian thetwo two exterior Renaissance exterior façades façadesarchit ofecture the of building the and contains wouldbuilding be would thethree first begalleries the such first toweron such the builtgroundtower inbuilt floor Seville in and Seville under four under on the the the influence first influence floor. of The of the the arches villas villas on ofof the the ground Italianthe Italian Renaissance. floorRenaissance. include Under Under original the the decoration lookout lookout towertower with isis plasterwork the entrance entrance and (Figure (Figure are supported 2a).2a). The The main by main columns of courtyard constitutes a prime example of Sevillian Renaissance architecture and contains courtyard constitutesimported Genoese a prime marble example (Figure of Sevillian 2b). These Renaissance arches form architecture part of an and interesting contains evolu- three galleries on the ground floor and four on the first floor. The arches on the ground three galleriestionary on the sequence ground of floor the andcourtyards four on in the the first main floor. palaces The of arches Seville, on and the groundcombine floor influences floor include original decoration with plasterwork and are supported by columns of include originalfrom decorationMudejar and with Gothic plasterwork art [7], ranging and are from supported the Palacio by columnsdel Rey Don of Pedro imported in the Real imported Genoese marble (Figure 2b). These arches form part of an interesting evolu- Genoese marbleAlcázar (Figure, through2b). the These Casa arches de Pilatos, form and part the of Palacio an interesting de las Dueñas evolutionary [3]. The first sequence-floor gallery tionary sequenceof the courtyard of the courtyards was recovered in the main and decoratedpalaces of inSeville, the second and combine half of the influences 20th century, after of the courtyards in the main palaces of Seville, and combine influences from Mudejar and from Mudejarbeing and partitioned Gothic art to [7],create ranging rooms from when the the Palacio building del Reywas Don Guest Pedro House in the Don Real Marcos [4]. Gothic art [7], ranging from the Palacio del Rey Don Pedro in the Real Alcázar, through the Alcázar, throughIn the the Casa ground de Pilatos,-floor and rooms, the Palacio the ceilings de las Dueñas with painted [3]. The Renaissancefirst-floor gallery decoration are Casa de Pilatos, and the Palacio de las Dueñas [3]. The first-floor gallery of the courtyard was of the courtyardpreserved, was recovered as are the and ceilings decorated of the in courtyardthe second galleries. half of the On 20th the century, first floor, after however, a recovered and decorated in the second half of the 20th century, after being partitioned to being partitionedlarge part to create of the rooms 16th -whencentury the ceilingsbuilding has was disappeared Guest House [8]. Don The Marcos garden [4]. in the third createIn rooms thecourtyard ground when the-floor has building another rooms, wasgallery the Guest ceilings with House two with floo Don paintedrs without Marcos Renaissance decorative [4]. decoration plasterwork. are preserved, as are the ceilings of the courtyard galleries. On the first floor, however, a large part of the 16th-century ceilings has disappeared [8]. The garden in the third courtyard has another gallery with two floors without decorative plasterwork.

(a) (b)

FigureFigure 2. (a) 2.Lookout(a) Lookout tower tower on the on façade. the façade. (b) Main (b) courtyard Main courtyard view. Authors’ view. Authors’ own photographs, own photographs, 2020. 2020. (a) (b) In the ground-floor rooms, the ceilings with painted Renaissance decoration are Figure 2. (a) Lookoutpreserved, tower on as the are façade. the ceilings (b) Main of courtyard the courtyard view. Authors’ galleries. own On photographs, the first floor, 2020. however, a large part of the 16th-century ceilings has disappeared [8]. The garden in the third courtyard has another gallery with two floors without decorative plasterwork. From the landing of the main staircase there is access to a mezzanine room that is currently used as the plenary hall for the Real Academia de Bellas Artes of Seville, where the ceiling with a geometric decoration that is studied in this research is located (Figure3). ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 3 of 17

From the landing of the main staircase there is access to a mezzanine room that is currently used as the plenary hall for the Real Academia de Bellas Artes of Seville, where the ceiling with a geometric decoration that is studied in this research is located (Figure 3). The first known historical document that refers to this room is a text written in 1542, which is located in the Archive of the Seville Cathedral (sección IV, Fábrica, Libro nº 377, fol. CCXCV-CCCII vto) and provides essential information regarding the state of the palace in the 16th century [9] [10]. This document describes the room, and confirms that the remarkable ceiling already existed: “E tiene un saquiçami de nueve y doze con sus deçen- didas...”. A “saquiçami” is a ceiling that hides its structural elements under the geometric decoration. The term “deçendidas” refers to the sloping sides. There is a mistake in the ISPRS Int. J. Geo-Inf. 2021, 10, 85 description however, since it speaks of a ceiling with interlocking patterns of nine-point3 of 17 and 12-point stars, although there are only interlocking patterns of eight-point and 12-point stars, as explained later.

FigureFigure 3.3. Mezzanine ceiling. ceiling. Authors’ Authors’ own own photograph, photograph, 2020. 2020.

1.2. GeneralThe first Objectives known historical document that refers to this room is a text written in 1542, whichThe is locatedpresent inresearch the Archive is the offirst the to Sevillebe carried Cathedral out on (seccithe mostón IV,important Fábrica, ceiling Libro of nº 377, fol.this CCXCV-CCCIIoutstanding Renaissance vto) and palace. provides Its current essential situation information seems fragile regarding due to the the state exist- of the palaceence of in major the 16th deformations century [9 that,10]. can This be document observed describeswith the naked the room, eye and and that confirms form thatthe the remarkableobject of this ceiling study. already existed: “E tiene un saquiçami de nueve y doze con sus deçendidas ... ”.In A order “saquiçami” to conserve isa the ceiling architectural that hides heritage, its structural it is essential elements to possess under up the-to geometric-date decoration.and accurate The graphic term documentation. “deçendidas” A refers well- todocumented the sloping monument sides. There has a is better a mistake chance in the descriptionof surviving however,over time sinceand through it speaks unpredictable of a ceiling withadversity. interlocking Even in patternsthe case of nine-pointits de- andstruction, 12-point its stars,intangible although values there would are onlybe safegua interlockingrded if patternsthere were of eight-pointgraphic documents and 12-point that allowed its reconstruction and virtual recreation or diffusion. stars, as explained later. For this reason, the main objective of this research is to provide a new and precise 1.2.graphic General documentation Objectives on a fragile architectural element, to be better known, suitably conserved, or restored on a scientific basis, and for its digital dissemination. For the first The present research is the first to be carried out on the most important ceiling of this time, this ceiling is represented by two complementary digital graphic technologies: a 3D outstanding Renaissance palace. Its current situation seems fragile due to the existence of major deformations that can be observed with the naked eye and that form the object of this study. In order to conserve the architectural heritage, it is essential to possess up-to-date and accurate graphic documentation. A well-documented monument has a better chance of surviving over time and through unpredictable adversity. Even in the case of its destruction, its intangible values would be safeguarded if there were graphic documents that allowed its reconstruction and virtual recreation or diffusion. For this reason, the main objective of this research is to provide a new and precise graphic documentation on a fragile architectural element, to be better known, suitably conserved, or restored on a scientific basis, and for its digital dissemination. For the first time, this ceiling is represented by two complementary digital graphic technologies: a 3D laser scanner that quantifies the existing deformations, and photogrammetry, which accurately visualises its details. The bibliography regarding Pinelo Palace and its history has been reviewed, as men- tioned in the introduction, as well as the design of this type of wooden ceiling in the 16th century, especially regarding the treatise by Diego López de Arenas of 1633. In addition, ISPRS Int. J. Geo-Inf. 2021, 10, 85 4 of 17

the documentation of several major architectural interventions of the 20th century that affected the ceiling has been uncovered in the Municipal Archives of Seville. The importance of graphic representation in architectural documentation is shown in the numerous manuscripts published in the proceedings of the latest “Graphical Her- itage” International Congress held in 2020 [11]. Heritage documentation techniques must avoid damaging it during data collection tasks and this objective is achieved using digital techniques such as photogrammetry and laser scanning [12]. The importance of these techniques, included in the ﬁeld of geomatics, in the sustainable conservation of heritage has been proved [13]; and they are also especially useful in the reconstruction of architectural heritage when it is damaged by natural disasters such as earthquakes [14]. Documenting heritage by means of laser scanners can be considered as one of the best techniques to reliably represent architectural assets [15–17], and the cloud of points derived from these scanners provides a useful tool for the evaluation of the measured objects [18]. Photogrammetry is a technique complementary to scanning when used in heritage documentation [19,20], and it is able to give images with accurate details thanks to the textural resolution. Scanning has been particularly useful in the detection of deformations, for example, in the muqarnas of the Alhambra [21,22] and as a basis for generating BIM (Building Information Modelling) models [23], as well as in architectural parametric modelling [24] and engineering [25]. This suggests that combining laser scanning and photogrammetry can provide accurate documentation of this 16th-century ceiling and its deformations, thereby developing a graphic methodology with no precedents in the literature on this type of architectural element. The application of photogrammetry to wooden ceilings has been used in [26], although possible deformations were not a reason for study. In order to understand and interpret the data obtained through geomatics, it is necessary to review the studies of Renaissance wooden ceilings: the layout and modulation of ceilings similar to the one we analyse in this manuscript [27,28], the historical evolution concerning the way of building the wooden ceilings [29] and a relevant example [30].

2. Materials and Methods 2.1. The Design of the Ceiling According to the Book by López de Arenas (1633) There are numerous studies on ceilings with wooden interlocking patterns in Spain and the Americas that present interesting examples [31,32]. One of the most extensive and well-known documents on the geometric layout of interlocking patterns is that of Prieto Vives [33], which brought together an uneven set of previously written articles, although it focused on mathematical speculations that failed to agree on the craft origins of these designs and therefore failed to formulate a coherent theory. Another outstanding study on interlocking patterns appeared in a short article by Fernández-Puertas [34] concerning the eight-point stars and was developed in another article by Donaire-Rodríguez [35]. Both stated that these designs were undertaken taking as a reference a unit of measurement that relates all the magnitudes, without the need to employ a compass, with simple geometric lines that give rise to various designs obtained solely using bevels. These ideas are now well-known and accepted thanks to the studies of Nuere- Matauco [36–38], and based on the book by Diego López de Arenas that included different rules on interlocking patterns that the carpenters used in Hispano-Muslim and Mudejar art. After a ﬁrst manuscript in around 1619, it was published in 1633 with the title Breve compendio de la carpintería de lo blanco y Tratado de Alarifes [39] (Figure4a). Interlocking patterns were also dealt with in another contemporary document by Fray Andrés de San Miguel that remained unpublished until the 20th century [40]: folios 72 to 92 include a section on carpentry based on documents that are now missing but have nothing to do with the book by López de Arenas. ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 5 of 17

terlocking patterns were also dealt with in another contemporary document by Fray Andrés de San Miguel that remained unpublished until the 20th century [40]: folios 72 to 92 include a section on carpentry based on documents that are now missing but have ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 5 of 17 nothing to do with the book by López de Arenas. According to López de Arenas, the design was made using only bevels, first drawing a pattern of lines as the basis for the type of interlocking pattern chosen. The thickness ISPRS Int. J. Geo-Inf. 2021, 10, 85 of the linearterlocking elements patterns was then were determined also dealt and with repeated in another at intervals. contemporary After drawing document5 of 17 by Fray these elementaryAndrés modules, de San Miguelthe set isthat obtained remained by itsunpublished juxtaposition, until with the common20th century units [40 of]: folios 72 to measurement92 and include proportion. a section on carpentry based on documents that are now missing but have nothing to do with the book by López de Arenas. According to López de Arenas, the design was made using only bevels, first drawing a pattern of lines as the basis for the type of interlocking pattern chosen. The thickness of the linear elements was then determined and repeated at intervals. After drawing these elementary modules, the set is obtained by its juxtaposition, with common units of measurement and proportion.

(a) (b)

FigureFigure 4. ( a4.) ( Covera) Cover of of the the book book by by Diego Diego L Lópezópez de de ArenasArenas (1633;(1633; reissue 1727) 1727).. (b (b) )Plate Plate 15r. 15r.

AccordingThe ceiling to studied López dein Arenas,the current the research design washas no made structural using onlyfunction bevels, in the first building drawing as a whole. It has two well-differentiated parts: the load-bearing elements, and the geo- a pattern of lines as the basis for the type of interlocking pattern chosen. The thickness ofmetric the linear decorative elements elements. was then The determinedload-bearing andelements, repeated “girders at intervals.” and “braces After”, are drawing hid- (a) (b) theseden elementary in its upper modules,part, and theperpendicular set is obtained to these by itsare juxtaposition, the smaller load with-bearing common elements, units of measurementcalledFigure “ 4.belts (a) Cover and” or “ proportion. battensof the book”. These by Diego smaller López elements de Arenas support (1633; reissue the flat 1727) wooden. (b) Plate surface 15r. upon whichThe the ceiling geometric studied ornamentation in the current modules research are has arranged. no structural function in the building as a whole.This It has ceiling two The well-differentiatedbelongs ceiling to studied a type in ofparts: the mixed current the interlockingload-bearing research has pattern elements, no structural of andeight function the-point geometric and in the building decorative12-point stars. elements.as Ina whole.other The words, Itload-bearing has thetwo 12 well-point- elements,differentiated star is a “girders”variation parts: ofthe and the load “braces”,modules-bearing generated are elements hidden by, and in the geo- the eight-point star, as encountered in other examples in the Iberian Peninsula, such as its upper part,metric and perpendiculardecorative elements. to these The are load the-bearing smaller elements, load-bearing “girders elements,” and “braces called”, are hid- the ceiling of the central nave of the Church of Santa Catalina in Seville. The drawing of “belts” or “battens”.den in Theseits upper smaller part, elementsand perpendicular support theto these flat woodenare the smaller surface load upon-bearing which elements, the aforementionedcalled “ beltsmodules” or “ calledbattens “cuartillejos”. These smaller”, appears elements in the support book by the Diego flat woodenLópez de surface upon the geometric ornamentation modules are arranged. Arenas (Figurewhich 4b) theand geometric also in that ornamentation of Fray Andrés modules de San areMiguel. arranged. This ceiling belongs to a type of mixed interlocking pattern of eight-point and 12-point The “cuartillejosThis ” ceilingare square belongs modules to a in type which of the mixed eight interlocking-point stars can pattern be traced of eight by -point and stars. In other words, the 12-point star is a variation of the modules generated by the various methods12-point using stars. bevels In other with words, different the 12 angles,-point star called is a variation“cuadrado of” the, “ocho modules” and generated by eight-point star, as encountered in other examples in the Iberian Peninsula, such as the “ataperfiles”th. Thee eight first-point two arestar, created as encountered by dividing in 180other° by examples the number in the that Iberian defines Peninsula, them such as ceiling of the central nave of the Church of Santa Catalina in Seville. The drawing of the (180°/4 and the180 °ceiling/8). The of thirdthe central is computed nave of from the Church the formula of Santa 45° Catalina− 90/n, wherein Seville. n is Thethe drawing of aforementionednumber of pointsthe modulesaforementioned of the star called in themodules “cuartillejos”, interlocking called “ appearspattern,cuartillejos in in this” the, appears case book n =in by 8 the (Figure Diego book L 5).byópez TheDiego de López de Arenascomplete (Figure geometricArenas4b) and (Figure alsoconstruction in 4b) that andof ofalso Fray the in Andr that eight of-époint sFray de SanAndrés and Miguel. 12 -depoint San starsMiguel. (Figure 6) is wellThe-known “cuartillejos” andThe explained “ arecuartillejos square in the”modules are aforementioned square in modules which publications thein which eight-point the. Finally,eight stars-point the can stars size be cantraced and be traced by bynumber various of methods ceilingvarious modules using methods bevels are usingfitted with to bevels the different dimensions with angles, different of calledthe angles, room “cuadrado”, to called be covered. “cuadrado “ocho” ”, and “ocho” and ◦ “ataperfiles”. The“ataperfiles first two”. The are createdfirst two by are dividing created by 180 dividingby the 180 number° by the that number defines that them defines them ◦ ◦ ◦ (180 /4 and 180(180/8).°/4 and The 180 third°/8). is The computed third is fromcomputed the formula from the 45 formula− 90/n, 45 where° − 90/n, n iswhere the n is the number of pointsnumber of the of points star in of the the interlocking star in the interlocking pattern, in thispattern, case in n this = 8 case (Figure n =5 8). (Figure The 5). The complete geometriccomplete construction geometric of construction the eight-point of the and eight 12-point-point andstars 12 (Figure-point 6 stars) is well- (Figure 6) is known and explainedwell-known in the and aforementioned explained in the publications. aforementioned Finally, publications the size and. Finally, number the of size and ceiling modulesnumber are fitted of ceiling to the modules dimensions are fitted of the to roomthe dimensions to be covered. of the room to be covered. Figure 5. Bevels to trace the eight-point star, according to López de Arenas (1633). Authors’ own drawing, 2020.

FigureFigure 5. Bevels 5. toBevels trace tothe trace eight the-point eight-point star, according star, accordingto López de to Arenas López (1633). de Arenas Authors’ (1633). own Authors’drawing, own2020. drawing, 2020.

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(a) (b) (a) (b) Figure 6. 6. CeilingCeiling details: details: (a) Eight (a) Eight-point-point star and star “ andcuartillejos “cuartillejos”.”. (b) “Cuartillejo (b) “Cuartillejo”” with a 12- withpoint a star. 12-point Authors’ star. own Authors’ pho- own Figure 6. Ceiling details: (a) Eight-point star and “cuartillejos”. (b) “Cuartillejo” with a 12-point star. Authors’ own photographs,photographs, 2020.2020. tographs, 2020. TheThe ceiling ceiling also also includes includes heraldic heraldic coats coats of arms arms and and other other decorative decorative elements, elements, “ﬂorones” The ceiling also includes heraldic coats of arms and other decorative elements, “floronesor “piñas”,” or “ whichpiñas” refer, which to therefer names to the ofnames the Pinelo of the andPinelo De and la Torre De la families Torre families who commis- who“florones commissioned” or “piñas the” construction, which refer of to the the building names (Figureof the Pinelo 7). and De la Torre families sionedwho commissioned the construction the construction of the building of the (Figure building7). (Figure 7).

Figure 7. Details of the heraldic coat of arms (Pinelo and De la Torre families). Authors’ own photographs,FigureFigure 7.2020. DetailsDetails of ofthe the heraldic heraldic coat coatof arms of arms(Pinelo (Pinelo and De and la Torre De lafamilies). Torre families). Authors’ own Authors’ pho- own tographs, 2020. photographs, 2020. 2.2. The Ceiling Consolidation in the 20th Century 2.2.2.2. The C Ceilingeiling C Consolidationonsolidation in in the the 20th 20th Century Century As the municipal architect, Jesús Gómez-Millán directed the consolidation work fundedAs by the the municipal Seville City architect,architect, Council Jesús in Jes theú s Gómez Pinelo Gómez-Mill- Millán palace á directed betweenn directed the 1967 the consolidation and consolidation 1971. Until work work 1981,fundedfunded other by by major the the Seville Sevillerestorations City City Councilwere Council carried in in the the out Pinelo Pinelo in the palace palace same between building, between 1967 1967directed and and by 1971. 1971. the Until ar- Until 1981, chitectother1981, Rafael majorother Manzanomajor restorations restorations Martos were and were carried promoted carried out byout in the in theDirección same same building, Generalbuilding, directedde directedBellas Artes by by the. the architect ar- RafaelchitectDocumentation ManzanoRafael Manzano Martos concerning Martos and promotedthe and nine promoted phases by the ofby Direccithe the work Direcciónón directed General General deby BellasGómez de Bellas Artes-Millán Artes. . is preservedDocumentation in the Municipal concerning concerning Archive the theof nine Seville, nine phases phases two of of ofthe which, the work work directedperformed directed by onGómez by the Gó mezza-mez-Mill-Millán is án is nine,preservedpreserved are the infilesin thethe titled MunicipalMunicipal “Comisión Archive Administradora of Seville, two del of Impuesto which, performed para la Prevención on on the the mezza- mezzanine, del Paroarenine, Obrero, the are ﬁles the nº titled files19/1967. titled “Comisi D/1368; “Comisiónón 32/1968. Administradora Administradora D/1371”. del del Impuesto Impuesto para para la la Prevenci Prevenciónón del del Paro Paro Obrero, nº 19/1967. D/1368; 32/1968. D/1371”. Obrero,The first nº 19/1967.-phase report D/1368; (August 32/1968. 1967– D/1371”.November 1967) describes the interventions The first-phase report (August 1967–November 1967) describes the interventions projectedThe on ﬁrst-phase the mezzanine report ceilings. (August Disassembly 1967–November of the two 1967) roof describesskirts on the the wooden interventions projected on the mezzanine ceilings. Disassembly of the two roof skirts on the wooden projected on the mezzanine ceilings. Disassembly of the two roof skirts on the wooden ceiling was planned, together with the removal of the old wooden beams that made up its slopes and their replacement with new metal girders, to later complete the gabled tile roof.

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ISPRS Int. J. Geo-Inf. 2021, 10, 85 7 of 17 ceiling was planned, together with the removal of the old wooden beams that made up its slopes and their replacement with new metal girders, to later complete the gabled tile roof.However, the third-phase report (May 1968–September 1968) changed the projected proposalHowever, and the the gabled third- roofsphase were report replaced (May 1968 by– aSeptember ﬂat roof. According1968) changed to this the document,projected it proposal and the gabled roofs were replaced by a flat roof. According to this document, it was planned to reinforce the heads of the old ceiling beams. In addition, two new metal was planned to reinforce the heads of the old ceiling beams. In addition, two new metal girders supported by the perimeter walls were introduced, arranged as two perpendicular girders supported by the perimeter walls were introduced, arranged as two perpendic- axes of the room, that is, parallel to the two lateral walls. The shorter transverse girder was ular axes of the room, that is, parallel to the two lateral walls. The shorter transverse placed at a lower elevation and the longer longitudinal girder placed above it. girder was placed at a lower elevation and the longer longitudinal girder placed above it. TheseThese newnew girdersgirders served as as anchors anchors for for metal metal tensioners, tensioners, fixed ﬁxed to tothe the old old wooden wooden beamsbeams that that support support thethe weight of of the the older older ceiling. ceiling. From From these these beams, beams, also also supported supported on on thethe side side walls, walls, other other wireswires were hung to to tighten tighten the the wooden wooden boards boards (Figure (Figure 8).8 ).

(a) (b)

FigureFigure 8. Hidden 8. Hidden structural structural elements. elements. (a ()a) Anchorages Anchorages ofof thethe 16th-century16th-century wooden wooden beams beams on on the the wall wall/new/new metal metal girders girders andand roof roof tie rods.tie rods. Photographs Photographs by by Ram Ramónón Queiro QueiroQuijada, Quijada, 2016.2016. ( (bb)) Schematic Schematic sections sections (hand (hand drawn drawn):): hypothesis hypothesis inclined inclined roof of disappeared wood (left)/current state with new concrete slab and metal beams (right). roof of disappeared wood (left)/current state with new concrete slab and metal beams (right). A report on the Technical Inspection of the Building (ITE), drawn up in June 2016 by A report on the Technical Inspection of the Building (ITE), drawn up in June 2016 by the architect Ramón Queiro Quijada for the Urban Planning Management of the Seville the architect Ramón Queiro Quijada for the Urban Planning Management of the Seville City Council, warned about the possible imminent danger of collapse of the ceiling. It City Council, warned about the possible imminent danger of collapse of the ceiling. It detected a deflection of approximately 0.15 m, which far exceeds that which is allowed detectedfor this type a deflection of material, of approximatelyand also uncovered 0.15 cracks m, which and small far exceeds fissures thatin the which wood. is It allowed was forstated this typethat this of material, could be anddue alsoto the uncovered deterioration cracks of the and upper small anchors fissures to in the the ceiling wood. and It was statedtogether that was this seen could as an be indication due to the that deterioration a collapse could of the occur upper with anchors fatal consequences. to the ceiling and togetherThe was artworks seen as housed an indication in the room that were a collapse transferred could to occur other with units fatal of the consequences. building itself Theand artworksthe state housedof conservation in the room of the were fastening transferred elements to other was unitsevaluated, of the with building a pre- itself andcautionary the state s ofhoring conservation of the ceiling of the being fastening planned. elements After reviewing was evaluated, the metal with girders a precautionary placed shoringby the architect of the ceiling Gómez being-Millán planned. and the cables After from reviewing which the the old metal wooden girders beams placed hang, by it the architectwas estimated Gómez-Mill that theán risk and of thedetachment cables from seemed which limited. theold wooden beams hang, it was estimatedTaking that all the these risk considerations of detachment into seemed account, limited. and in order to ensure suitable con- servationTaking and all thesemonitoring considerations in the future, into it account, was decided andin toorder utilise to digital ensure graphic suitable technol- conserva- tionogies and to monitoringquantify the incurrent the future, deformations: it was decided a first for to this utilise type digital of ceiling. graphic technologies to quantify the current deformations: a first for this type of ceiling. 2.3. Graphic Survey: Material and Method 2.3. GraphicTwo graphic Survey: surveys Material of andthe ceiling Method have been carried out, based on 3D laser scanners andTwo photogrammetry, graphic surveys respectively, of the ceiling which have have been both carried proven out, to be based effective on 3D [21 laser,24,25 scanners]. and photogrammetry,The first method respectively,aimed to quantify which the have deformation both provens, with to beaneffective approach [21 similar,24,25 ].to thatThe in previousfirst method work aimed [22,2 to3].quantify Vertical the deformations deformations, are with better an observed approach if similar the walls, to that inwindow, previous and work floor [22 of,23 the]. Verticalroom are deformations also included arein the better survey. observed The scans if the carried walls, out window, al- andlow floor us to of ascertain the room theare whole also room included with homogeneous in the survey. precision. The scans carried out allow us to ascertainOn the the whole other hand, room the with photogrammetric homogeneous precision. method has been used to achieve a tex- turedOn three the other-dimensional hand, the model photogrammetric with a higher methodimage resolution, has been usedin such to achievea way that a textured or- three-dimensionalthophotos can be derived model withand material a higher details image can resolution, be visualised. in such a way that orthophotos can be derived and material details can be visualised. The material used to obtain these surveys included the following: Leica C10 and BLK360 laser scanners were used. The C10 has a dual-axis compen- sator with 1” accuracy and with 6 mm accuracy in position determination. The software ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 8 of 17

The material used to obtain these surveys included the following: Leica C10 and BLK360 laser scanners were used. The C10 has a dual-axis compen- ISPRS Int. J. Geo-Inf. 2021, 10, 85 sator with 1’’ accuracy and with 6 mm accuracy in position determination.8 of 17 The software used for the registration and for the processing of the point cloud were Cyclone 360 and 3DReshaper, respectively. used for the registrationThe photogrammetry and for the processing was carried of the point out with cloud a were Sony Cyclone Alpha 7 360 ILCE and-7K Full frame (35 3DReshaper, respectively.mm) 24.3 Mpix camera and a 28-70 mm F3.5-5.6 lens. In order to obtain photographs with The photogrammetrya greater approximatio was carried outn and with resolution, a Sony Alpha the 7 camera ILCE-7K was Full mounted frame (35 mm)on a pole of approxi- 24.3 Mpix cameramately and 2.5 a 28-70 m in mmheight. F3.5-5.6 In addition, lens. In supplementary order to obtain lighting photographs was necessary with a due to the lack greater approximationof natural and light resolution, in the room the camera and the was dark mounted colour on of a the pole ceiling of approximately itself. To this end, a focus of 2.5 m in height.0.60 In × addition, 0.60 m was supplementary mounted on lighting an auxiliary was necessary pole. The due data to theprocessing lack of was carried out natural light inusing the room the photogrammetric and the dark colour software of the ceilingAgisoft itself. Metashape To this version end, a focus 1.5.2. of 0.60 × 0.60 m was mounted on an auxiliary pole. The data processing was carried out using the photogrammetric2.3.1. Scanner software Laser Agisoft Metashape version 1.5.2.

2.3.1. Scanner LaserMost of the scans were carried out with the BLK360 scanner due to its faster speed and its ability to capture images in Hight Definition Range (HDR), although it does not Most of the scans were carried out with the BLK360 scanner due to its faster speed capture levelled scans. To obtain the whole set in the same reference and levelled system, and its ability to capture images in Hight Deﬁnition Range (HDR), although it does not the scanning process started from the E-1 and E-2 stations of the C10 scanner, which can capture levelled scans. To obtain the whole set in the same reference and levelled system, the scanning processbe levelled started and from oriented the E-1 to and a predetermined E-2 stations of thedirection C10 scanner, (in our whichcase, the can courtyard gallery be levelled andwhere oriented E-1 to was a predetermined located). direction (in our case, the courtyard gallery where E-1 was located).The C10 capture parameters both in E-1 and E-2 included the following: capture of The C10 capturepoints parametersat medium spatial both in resolution E-1 and E-2 at included which each the following:point is separated capture from of its neighbours points at mediumby spatial 1 cm assuming resolution a at plane which located each point 10 ism separated away; the from image its neighbours resolution captured by the by 1 cm assumingscanner a plane was located 1920 10× 1920 m away; pixels. the The image remaining resolution scans captured were by carried the scanner out with the following was 1920 × 1920BLK360 pixels. parameters:The remaining medium scans were spatial carried resolution out with (1 the cm following at 10 m) BLK360 while the images were parameters: mediumtaken spatialin HDR resolution at those (1scan cm stations at 10 m) whilewhere the the images lighting were conditions taken inHDR were scarce or where at those scan stationsthere was where a lot the of lighting light contrast. conditions were scarce or where there was a lot of light contrast. The registration between the C10 and BLK360 scans was made through the C10 lo- The registrationcated betweenin E-1 and the the C10 BLK3 and BLK36060 located scans in was BLK made-1. Figure through 9 shows the C10 the located path followed by the in E-1 and theBLK BLK360 scanner located until in BLK-1.reaching Figure the mezzanine9 shows the where path followedthe ceiling by under the BLK the study is located scanner until reaching(Figure the 9). mezzanine Figure 10 whereshows the a detail ceiling of under the thescan study distribution is located inside (Figure the9 ). mezzanine room Figure 10 shows(Figure a detail 10). of the scan distribution inside the mezzanine room (Figure 10).

(a) (b)

FigureFigure 9. Scan 9. Scan path path and distribution.and distribution (a) General. (a) General view. view (b) Fit. (b and) Fit error and valueserror values of the scans.of the scans.

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ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 9 of 17

FigureFigure 10. 10.Detail Detail of of the the scanner scanner station station positions positions within within the the mezzanine mezzanine room. room. Figure 10. Detail of the scanner station positions within the mezzanine room. TheThe globalglobal point point cloud cloud composed composed of of scan scan stations stations E-1, E- BLK-1,1, BLK- and1, and ET-1 ET to-1 ET-11to ET- is11 is mademadeThe upup global of of 124,093,128 124,093,128 point cloud points, points, composed while while of the thescan cloud cloud stations corresponding corresponding E-1, BLK-1, only and only toET theto-1 theto room ET room-11 contains is contains 60,168,936made60,168,936 up of points points124,093,128 and and is points,is made made while up up of of the the cloud ET-6 ET- tocorresponding6 to ET-11 ET-11 scan scan stations. only stations. to the room contains 60,168,936 points and is made up of the ET-6 to ET-11 scan stations. TheThe registrationregistration of of the the scans scans was was carried carried out out visually visually using using Cyclone Cyclone 360 360 software software in in The registration of the scans was carried out visually using Cyclone 360 software in orderorder toto maintainmaintain greatergreater controlcontrol over over the the results results (Figure (Figure9b). 9b). For For each each contiguous contiguous pair pair of oforder scans, to maintain their plan greater projections control wereover the visually results aligned (Figure (Figure 9b). For 11 eacha), andcontiguous then displayed pair of in scans, their their plan plan projections projections were were visually visually aligned aligned (Figure (Figure 11a), and 11a), then and displayed then displayed in in elevation and, if necessary, levelled (Figure 11b; in this image the slope of the lower scan elevation and, and, if ifnecessary, necessary, levelled levelled (Figure (Figure 11b; 11bin this; in image this image the slope the o slopef the lower of the scan lower scan has been intentionally exaggerated). After levelling (Figure 11c), the lower scan was moved has been been intentionally intentionally exaggerated). exaggerated). After After levelling levelling (Figure (Figure 11c), the 11c lower), the scan lower was scan was vertically until the two scans were roughly aligned (Figure 11d), to ﬁnally activate the moved vertically vertically until until the the two two scans scans were were roughly roughly aligned aligned (Figure (F 11digure), to 11d finally), to activate finally activate optimisation algorithm which completed the alignment with more accuracy and reported the optimisationoptimisation algorithm algorithm which which complete completed thed alignment the alignment with more with accuracymore accuracy and re- and re- the ﬁtting error, which in our case was 1.6 mm (Figure 11e). The two scan registered porteded the the fitting fitting error, error, which which in ourin ourcase case was was1.6 mm 1.6 (Figuremm (Figure 11e). The 11e). two The scan two regis- scan regis- withtered itswith true its colourtrue colour areshown are shown in Figure in Figure 11f 11f where where the the yellow yellow triangles triangles represent represent their scantered positions. with its true colour are shown in Figure 11f where the yellow triangles represent their scan scan positions positions. .

Figure 11. Manual recording of two scans with indication of the fitting error. Figure 11. Manual recording of two scans with indication of the ﬁtting error. FigureIn 1 the1. Manual optimisation optimisation recording phase, phase, of twothe the ssoftwarecans software with strives indication strives to make to of make the the fitting thebest best error.registration registration using using pointspoints from overlapping overlapping scans scans and and if it if succeeds, it succeeds, then then it marks it marks the links the that links took that part took in part inthe the registrationIn registration the optimisation with with straight straight phase, lines. lines. the The software The colour colour ofstrives the of the links to linksmake indicates indicates the best the theregistrationregistration registration using suitability, whereby green is the indicator of a good registration. In this case, the error suitability,points from whereby overlapping green scans is the and indicator if it succeeds, of a good then registration. it marks the In thislinks case, that thetook error part in made in the whole set (Bundle) was 3 mm (Figure 9b). Other quality parameters regard- madethe registration in the whole with set (Bundle) straight was lines. 3 mm The (Figure colour9b). of Other the quality links indicates parameters the regarding registration ing the registration refer to the existing overlap between scan stations (% of object sur- thesuitability, registration whereby refer togreen the existingis the indicator overlap betweenof a good scan registration. stations (% In of this object case, surfaces the error faces covered by two scans), registration strength (the better the three directions of space coveredmade in by the two whole scans), set registration (Bundle) was strength 3 mm (the (Figure better 9b). the threeOther directions quality parameters of space (x, regard- y, z) (x, y, z) are covered, the greater the registration strength) and cloud-to-cloud error. areingcovered, the registration the greater refer the to registration the existing strength) overlap and between cloud-to-cloud scan stations error. (% of object surfaces covered by two scans), registration strength (the better the three directions of space (x, y, z) are covered, the greater the registration strength) and cloud-to-cloud error.

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To better understand the spatial environment, a perspective view of the point cloud To better understand the spatial environment, a perspective view of the point cloud was obtained, fromTo better the gallery understand to the the mezzanine spatial environment, ﬂoor passing a perspective through the view main of staircasethe point cloud was obtained, from the gallerywas obtained, to the mezzanine from the galleryfloor passing to the throughmezzanine the floor main passing staircase through the main staircase (Figure 12). (Figure 12). (Figure 12).

Figure 12. 3DFigur orthographice 12. 3D viewsorthographic extracted Figurview fromse extracted 12. the 3D point orthographic from cloud the topoint view better clouds extracted understand to better from understand the the different point thecloud levels different tofor better the understand mezzanine the different (a) and the towerlevels above for the staircasemezzanine (b ().alevels) Central and thefor image thetower mezzanine shows above thethe (a polygonalstaircase) and the ( b sectionstower). Central above (yellow) image the staircase andshows the the viewpoints(b ).po- Central VP1 image and shows the po- VP2; the left imagelygonal was section observeds (yellow) from and VP1lygonal the and viewpoints section the rights (yellow) imageVP1 and wasand VP2 observedthe; the viewpoints left fromimage VP1 VP2. was and observed VP2; the from left VP1 image was observed from VP1 and the right image was observedand the from right VP2 image. was observed from VP2. 2.3.2. Photogrammetry 2.3.2. Photogrammetry 2.3.2. Photogrammetry Ceiling photographs were taken by bringing the camera closer with a pole, with Ceiling photographs wereCeiling taken photographs by bringing were the camera taken by closer bringing with a the pole, camera with closer with a pole, with additional lighting provided on another pole (Figure 13a). In this way, 89 photographs additional lighting providedadditional on another lighting pole provided (Figure 13a).on another In this pole way, (Figure 89 photographs 13a). In this way, 89 photographs were obtained (Figure 13b). were obtained (Figure 13b).were obtained (Figure 13b).

(a) (a) (b) (b) Figure 13. Photogrammetry on the mezzanine: (a) Data capture. (b) 3D photogrammetric model. FigureFigure 13. 13. PhotogrammetryPhotogrammetry on the on mezzanine: the mezzanine: (a) Data (a) Datacapture capture.. (b) 3D ( bphotogrammetric) 3D photogrammetric model. model.

The focal lengthThe of focal the camera lengthThe focal ofwas thelength set camera to of28 the mm was camera and set the towas 28resolution set mm to and28 to mm the24.3 and resolution Mp the for resolution to 24.3 to Mp 24.3 for Mp for each image. Theeach photograph image.each The alignmentimage. photograph The was photograph alignment computed wasalignment using computed Metashape was usingcomputed software Metashape using with Metashape software with software the with the Accuracy parameter set to medium. The dense point cloud was obtained with medium Accuracy parameterthe Accuracy set to parameter medium. set The to densemedium. point The cloud dense was point obtained cloud withwas obtainedmedium qualitywith medium quality that computed 30,957,566 points, and the model mesh was processed setting the that computedquality 30,957,566 that computed points, and30,957,566 the model points, mesh and was the processedmodel mesh setting was theprocessedFaces count setting the Faces count parameter to high, thereby obtaining a total of 6,191,513 faces. Finally, the parameter toFaces high, count thereby parameter obtaining to high, a total thereby of 6,191,513 obtaining faces. a total Finally, of 6,191,513 the texture faces. Finally, was the texture was computed by setting the following parameters: Mapping mode (Generic), computed bytexture setting was the computed following by parameters: setting the followingMapping mode parameters:(Generic), Mappingblending mode mode (Generic), blending mode (Mosaic) and Texture size/count (8000 × 1). The alignment adjustment was (Mosaic) andblendingTexture mode size/count (Mosaic)(8000 and Texture× 1). Thesize/count alignment (8000 × adjustment 1). The alignment was carried adjustment out was carried out by means of controlcarried pointsout by whosemeans coordinatesof control points were whoseobtained coordinates from the scanswere obtained from the scans by means of control points whose coordinates were obtained from the scans recorded in recorded in the previousrecorded phase; those in the coordinates previous phase; were extractedthose coordinates using the were 360º extractedvisual using the 360º visual the previous phase; those coordinates were extracted using the 360º visual capabilities capabilities of Jetstream softwarecapabilities for ofeach Jetstream scan station. software The for total each (bundle) scan station. mean errorThe total was (bundle) mean error was of Jetstream software for each scan station. The total (bundle) mean error was 6.5 mm 6.5 mm (Figure 14). This6.5 figure mm also(Figure offers 14). an This orthogonal figure also image offers of thean orthogonalceiling with image the of the ceiling with the (Figure 14). This ﬁgure also offers an orthogonal image of the ceiling with the location of location of the control pointslocation that ofwere the employedcontrol points in the that adjustment. were employed in the adjustment. the control points that were employed in the adjustment.

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ISPRS Int. J. Geo-Inf. 2021, 10, 85 11 of 17 By using the parametric values indicated above, an orthophotograph of high spatial ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 11 of 17 and spectral resolution with a pixel size of 0.5 mm was reached.

By using the parametric values indicated above, an orthophotograph of high spatial and spectral resolution with a pixel size of 0.5 mm was reached.

(a) (b)

FigureFigure 14. 14. PhotogrammetricPhotogrammetric adjustment: adjustment: (a ()a Coordinates) Coordinates and and error error adjustment adjustment.. (b (b) )Control Control-point-point location location..

By using the3. Results parametric and valuesDiscussion indicated above, an orthophotograph of high spatial (a) (b) and spectral resolutionThe with results a pixel are derived size of 0.5from mm the was point reached. cloud obtained with the scan and from the Figure 14. Photogrammetric adjustment:photogrammetric (a) Coordinates and 3D errormodel. adjustment The scan. (b provides) Control- pointa 3D location structure. that integrates the walls 3. Results and Discussionand the ceiling, thereby enabling their deformations to be measured. Photogrammetry 3. Results and Discussion The resultsallows are derived material from details the to point be visualised cloud obtained thanks to with the high the scan-resolution and from texturing the of the 3D photogrammetricThe results surfaceare 3D derived model. model. from The the scan point provides cloud obtained a 3D structure with the that scan integrates and from the the walls andphotogrammetric the ceiling, thereby 3DThe model. first enabling Theanalysis scan their detected provides deformations signific a 3D antstruct to geometric beure measured. that deformationsintegrates Photogrammetry the that walls may have already allowsand the material ceiling, existed detailsthereby in toenabling the be visualisedoriginal their construction, deformations thanks to theas to often high-resolution be measured. occurs in historicPhotogrammetry texturing buildings. of the The 3D image ob- surfaceallows material model. taineddetails fromto be thevisualised point cloud thanks shows to the a high plan-resolution that theoretically texturing should of the be3D rectangular, but surface model. The ﬁrst analysisactually detected has different signiﬁcant lengths geometric on its parallel deformations sides: the longest that may sides have differ already by 0.065 m. and The first analysisthe smaller detected ones signific differ ant0.091 geometric m (Figure deformations 15). that may have already existed in the original construction, as often occurs in historic buildings. The image existed in the original construction, as often occurs in historic buildings. The image ob- obtained from the point cloud shows a plan that theoretically should be rectangular, but tained from the point cloud shows a plan that theoretically should be rectangular, but actually has different lengths on its parallel sides: the longest sides differ by 0.065 m. and actually has different lengths on its parallel sides: the longest sides differ by 0.065 m. and the smaller ones differ 0.091 m (Figure 15). the smaller ones differ 0.091 m (Figure 15).

Figure 15. Ceiling dimensions from point cloud (orthogonal projection).

FigureFigure 15.15. Ceiling dimensions dimensions from from point point cloud cloud (orthogonal (orthogonal projection). projection).

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The differences in measurements on the room ﬂoor are not visible to the naked eye The differences in measurements on the room floor are not visible to the naked eye fromfrom inside insideThe differences the the room. room. inHowever,However, measurements the ceiling ceiling on the deformations deformations room floor areare are indeed not indeed visible perceptible. perceptible. to the naked In order In eye order totofrom provide provide inside a a clearerthe clearer room. ﬁrst firstHowever, view view of the of the theceiling deformations, deformations, deformations two two are perpendicular perpendicularindeed perceptible. interior interior In order section- sec- elevationstionto provide-elevations were a clearerobtained,were obtained, first cutting view cutting through of the through deformations, the centrethe centre of thetwo of the room perpendicular room (Figure (Figure 16 interior).16). section-elevations were obtained, cutting through the centre of the room (Figure 16).

(a) (b) (a) (b) FigureFigure 16. 16.Sections Sections through through the the mezzaninemezzanine centre: ( (aa)) Longitudinal Longitudinal.. (b ()b Transversal.) Transversal. Figure 16. Sections through the mezzanine centre: (a) Longitudinal. (b) Transversal. ToTo quantify quantify thethe magnitudesmagnitudes of the main main deformations, deformations, three three longitudinal longitudinal sections sections To quantify the magnitudes of the main deformations, three longitudinal sections (parallel(parallel to to the the longest longest sidessides of the room) room) were were made made and and different different heights heights were were sampled sampled therein,(parallel whereby to the longest the most sides significant of the room) data werewas chosenmade and (Figure different 17). heights were sampled therein,therein, whereby whereby the the most most signiﬁcant significant datadata was chosen (Figure (Figure 17). 17).

(a) (b) (a) (b) Figure 17. Mezzanine sections: (a) Sections AA′, BB′, CC′. (b) Heights in sections AA′, BB′, CC′. FigureFigure 17. Mezzanine17. Mezzanine sections: sections: (a )(a Sections) Sections AA AA0,′ BB, BB0,′, CC CC0′.(. (b) Heights in in sections sections AA AA′, 0BB, BB′, CC0, CC′. 0. The measurement data is unexpected, since it would be logical to find the greatest deformationTheThe measurement measurement in the ceiling data data centre. isis unexpected,unexpected, However, whensince since observingit it would would be section be logical logical BB to′ toorfind ﬁndits theorthogonal the greatest greatest 0 deformationviewdeformation (Figure in 18in the ),the it ceiling isceiling verified centre. centre. that However,However, the greatest when height observing observing differences section section are BB found BB′ oror i ts1.05 its orthogonal orthogonalm from viewtheview centre (Figure (Figure of 18the 18), ),room it it is is veriﬁed withverified heightthat that differences thethe greatestgreatest of height height0.238 m differences differences from B and are are0.239 found found m from 1.05 1.05 mB′. m fromThe from thedifferencethe centre centre of inof the heightthe room room from with with both height height B and differencesdifferences B′ to the ofcentre 0.238 is m m 0.2 from from20 m. B B andTherefore and 0.239 0.239 m, mbetween from from B′. B theThe0. The difference in height from both B and B′ to the centre is 0.220 m. Therefore, between the differencelowest point in height of the fromceiling both and Bthe and centre B0 to there the centreis a height is 0.220 difference m. Therefore, of 0.018 betweenm. These the lowest point of the ceiling and the centre there is a height difference of 0.018 m. These lowestresults point are coherent of the ceiling with the and existence the centre of anchors there isplaced a height in the difference 1968 consolidation of 0.018 m. work These results are coherent with the existence of anchors placed in the 1968 consolidation work resultsdirected are by coherent Goméz- withMillán the to existencealleviate the of stress anchorses derived placed from in the its 1968 own consolidationweight. work directed by Goméz-Millán to alleviate the stresses derived from its own weight. directed by Goméz-Millán to alleviate the stresses derived from its own weight.

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((aa)) ((bb))

FigureFigureFigure 18. 18.18.Longitudinal LongitudinalLongitudinal cross-section crosscross--sectionsection through throughthrough the thethe roomroomroom centre centre includingincluding measurementmeasurement measurement ofof of deformations:deformations: deformations: ((aa)) S (Saectionection) Section BB'BB'.. BB’. (b)( Section-perspective(bb)) SSectionection--perspectiveperspective view. view.view.

TheTheThe lack lack lack of of of uniformity uniformity uniformity in in in the the the deformations deformations deformations is is isalso also also observed observedobserved in inthe in the the north-south north north--southsouth trans- versetransversetransverse direction. direction.direction. While WhileWhile in section inin section section A0B0 CAA0′′BBthere′′CC′′ therethere is a is descendingis a a descendingdescending slope slopeslope from fromfrom north north north to south,toto insouth,south, section inin section ABCsection there ABCABC is therethere an ascending isis anan ascendingascending slope slopeslope from fromfrom A to AA B toto and BB andand descending descendingdescending from fromfrom B B toB toto C CC with differentwithwith different different values values values of increments: of of increments: increments: 0.034 m0.0340.034 and m m 0.012 and and m0.0.012012 respectively. m m respectively. respectively. This is ThisThis also is is explained also also ex- ex- by plained by the placement of various anchors during the consolidation work in the late theplained placement by the of placement various anchors of various during anchors the consolidationduring the consolidation work in the work late 20thin the century. late 20th20th century.century. On the other hand, the roof surface (Figure 19) has also been reconstructed through OnOn thethe otherother hand,hand, thethe roofroof surfacesurface ((FigureFigure 1919)) hashas alsoalso beenbeen reconstructedreconstructed throughthrough photogrammetry, and a textured 3D model was obtained that may be of great interest for photogrammetry,photogrammetry, andand aa texturedtextured 3D3D modmodelel waswas obtainedobtained thatthat maymay bebe ofof greatgreat interestinterest forfor future conservation or restoration work, and for the heritage communication. futurefuture conservationconservation oror restorationrestoration workwork,, andand forfor thethe heritageheritage communication.communication.

((aa)) ((bb))

FigureFigureFigure 19. 19.19.General GeneralGeneral view viewview and andand details detailsdetails of the ofof mezzanine thethe mezzaninemezzanine ceiling ceilingceiling from photogrammetry:fromfrom photogrammetry:photogrammetry: (a) 3D ( surface(aa)) 3D3D surfacesurface model. modelmodel (b) 3D.. textured((bb)) 3D3D tex-tex- model. turedtured modelmodel.. The 3D photogrammetric model has made it possible to obtain orthophotographs from theTheThe central 3D3D photogrammetricphotogrammetric horizontal part model model of the ceilinghas has mademade and itit from possiblepossible its tilted toto obtainobtain planes orthophotographsorthophotographs so that their details canfromfrom be thethe visualised centralcentral horizontalhorizontal with a high partpart resolution ofof thethe ceilingceiling (Figure andand 20 fromfrom). The itsits tilted tiltedtilted planesplanesplanes aresoso thatthat laid theirtheir ﬂat inde-de- their tails can be visualised with a high resolution (Figure 20). The tilted planes are laid flat in truetails magnitude can be visualised along withwith thea high central resolution part. Geometric (Figure 20). irregularities The tilted planes or deformations are laid flat in of the their true magnitude along with the central part. Geometric irregularities or defor- horizontaltheir true and magnitude tilted planes along are with clearly the centralvisible on part. the Geometric edges. irregularities or defor- mationsmations ofof thethe horizontalhorizontal andand tiltedtilted planesplanes areare clearlyclearly visiblevisible onon thethe edges.edges.

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Figure 20. Ceiling orthoimage with the tilted side planes laid flat. Figure 20. Ceiling orthoimage with the tilted side planes laid ﬂat.

4. Conclusions InIn order order to to ascertain, ascertain, conserve, conserve, and and disseminate disseminate architectural architectural heritage, heritage, it is essential it is essential to attain suitable suitable digital digital images. images. A Agraphically graphically well well-documented-documented landmark landmark will willalways always have a a better better chance chance of of surviving surviving the the passage passage of oftime, time, an un anpredictable unpredictable catastrophe, catastrophe, or or unfortunate human human interventions. interventions. In Inthe the worst worst scenario, scenario, when when the thearchitectural architectural heritage heritage is destroyed by some misfortune, its memory can be preserved if there are images that is destroyed by some misfortune, its memory can be preserved if there are images that facilitate its material reconstruction or virtual recreation. facilitate its material reconstruction or virtual recreation. For the documentation and analysis of this 16th-century ceiling in the Pinelo Palace For the documentation and analysis of this 16th-century ceiling in the Pinelo Palace in Seville, this research has considered its historical background and has followed a in Seville, this research has considered its historical background and has followed a methodology based on two complementary digital data captures: using a 3D laser scan- methodologyner, and photogrammetry. based on two complementary digital data captures: using a 3D laser scanner, and photogrammetry. It has been found that in a room that should theoretically be rectangular, there are differences of 0.065 m when comparing the longest sides and 0.091 m on the shortest sides. These irregularities suggest that the Renaissance palace was able to reuse the

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walls of a previous medieval building, in accordance with historical studies referred in the introduction. After having analysed several geometric modules of the ceiling, it was found that it is made up of interlocking patterns of eight-point and 12-point stars, and not, as a text from 1542 erroneously describes it, of nine- and 12-point stars. In the final orthoimage (Figure 20), it can easily be observed that the ceiling is composed of “cuartillejos” or modules with a square base, but its modulation is altered in the central part, where a small strip is duplicated, to fit the design to the room dimensions. From this it follows that there was no unitary project for the whole building: the ceiling design had to be fitted to a room whose walls were probably deformed. According to the historical documentation consulted, the ceiling was consolidated under the direction of the architect Jesús Gómez-Millán in around 1967–1970. The tile roof was replaced with a flat concrete floor and the ceiling was hung from two new metal beams. The deformations came into existence when this consolidation was completed approximately 50 years ago, but until now it had not been accurately quantified. In the sections, the maximum ceiling deformation does not occur in the centre: the lowest point is at 1.05 m on both sides from the centre. This is explained by the placement of anchors that released stress due to their weight, although the maximum deformations are large: 0.238 and 0.239 m. A lack of uniformity has also been detected in the deformations: in the cross-sections towards the eastern end the deformations are descending, and towards the western end they are staggered. Therefore, under the direction of Gómez-Millán, wire rods were placed that successfully improved safety and stability, but also caused the current irregular deformations. The high-resolution orthoimage provided allows the details of the ceiling to be viewed with precision. Without a thorough knowledge of what is to be preserved or restored, it remains impossible to propose suitable measures for its protection. The rigorous digital graphic documentation is expected to serve as a starting point for a future scientific plan for the conservation of this unique deformed ceiling and to disseminate on the web the image of a beautiful architectural element of the rich heritage of southern Europe.

Author Contributions: Juan Francisco Reinoso-Gordo, Antonio Gámiz-Gordo and PPedro Barrero- Ortega all took part in the entire research process. All authors have read and agreed to the published version of the manuscript. Funding: This research has been funded by internationalisation grants to the Instituto Universitario de Arquitectura y Ciencias de la Construcción (IUACC) of the VII Plan Propio de Investigación y Transferencia in the University of Seville. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Acknowledgments: The present research has been made possible thanks to the collaboration of members and staff of the Real Academia de Bellas Artes de Santa Isabel de Hungría de Sevilla and Real Academia Sevillana de Buenas Letras; Carpintería Los Tres Juanes; Ramón Queiro Quijada; Rafael Manzano Martos. The authors are also grateful for the support from the research group Expregrafica, Lugar Arquitectura y Dibujo (PAIDI-HUM-976), Programa de Doctorado en Arquitectura, Instituto Universitario de Arquitectura y Ciencias de la Construcción from the University of Seville; the research group Ingeniería Cartográfica (PAIDI-TEP-164) from the University of Jaén; and the Survey and Modelling Laboratory (SMlab) from the University of Granada. Conflicts of Interest: The authors declare there to be no conflict of interest.

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