3D Modeling with Reusable and Integrated Building Blocks

The creation of highly detailed components presented in this paper builds upon our previously introduced technique for creating complete models from only a small number of measured seed points. Here, we aim at increasing the level of automation in 3D reconstruction of scenes from a small number of images. We build highly detailed model components, for example; windows, columns, groin-vaulted ceilings elements, and arches with large number of automatically created points. The components are created to be reusable in other parts of the model, or any other model, which are similar in shape, but may vary in dimensions. Our approach works directly on the images and performs accurate transformations and scaling automatically without trials and errors. We developed a copy and paste procedure that automatically re-triangulates the base model to account for the pasted element. By creating reusable higher-level building blocks that can be integrated to form a highly detailed model, a growing library of image-based reusable components will materialize. This will significantly reduce the effort, time, and expertise required to create detailed 3D models from images.La cr\ue9ation d'\ue9l\ue9ments hautement d\ue9taill\ue9s, pr\ue9sent\ue9e dans cet article, est fond\ue9e sur notre technique ant\ue9rieurement expos\ue9e de cr\ue9ation de mod\ue8les complets \ue0 partir de seulement un petit nombre de points-graines mesur\ue9s. Notre but \ue9tait d'accro\ueetre le niveau d'automatisation dans la reconstruction 3D de sc\ue8nes \ue0 partir d'un petit nombre d'images. Nous avons \ue9labor\ue9 des \ue9l\ue9ments de mod\ue9lisation hautement d\ue9taill\ue9s, repr\ue9sentant par exemple des fen\ueatres, des colonnes, des parties de vo\ufbte d'ar\ueates et des arcs, avec un grand nombre de points cr\ue9\ue9s automatiquement. Les \ue9l\ue9ments sont cr\ue9\ue9s pour \ueatre r\ue9utilisables dans d'autres parties du mod\ue8le ou dans n'importe quel autre mod\ue8le, \ue0 condition d'avoir une forme semblable avec des dimensions diff\ue9rentes. Notre m\ue9thode s'applique directement aux images et effectue des transformations exactes et des mises \ue0 l'\ue9chelle automatiques sans approximations successives. Nous avons d\ue9velopp\ue9 une proc\ue9dure de copiage et collage qui retriangule automatiquement le mod\ue8le de base pour tenir compte des \ue9l\ue9ments coll\ue9s. La cr\ue9ation de blocs modulaires r\ue9utilisables de haut niveau pouvant \ueatre int\ue9gr\ue9s pour former un mod\ue8le hautement d\ue9taill\ue9, permettra de constituer une biblioth\ue8que grandissante d'\ue9l\ue9ments imag\ue9tiques r\ue9utilisables. Il sera ainsi possible de r\ue9duire de beaucoup les efforts, le temps et l'expertise n\ue9cessaires pour cr\ue9er des mod\ue8les 3D d\ue9taill\ue9s \ue0 partir d'images.NRC publication: Ye

Digital photogrammetry and laser scanning in cultural heritage survey

A joint project between the Interdept. Research Center of the University of Padova (CIRGEO), a research group of Istituto Tecnico per la Ricerca Scientifica e Tecnologica (IRST) of Trento and the Visual Information Technology group (VIT) of the NRC Canada, in Ottawa, has been undertaken, with the main aim to create a set of 3D models of an historical building by means of photogrammetry and laser scanning-based surveying techniques. Beside the investigation of their geometric accuracy, a photo-realistic representation suited for interactive navigation and manipulation in VR environment was a further objective of thie project. To this aim, the main room in the Aquila tower in Buonconsiglio castle (Trento, Italy) was choosen, as it featured a relative simple geometry along with artistically and historically very precious frescoed walls. In this paper a description of both surveying and modeling procedures adopted and results of a comparison test between employed techniques are presented

Digital Photogrammetry and Laser Scanning in Cultural Heritage Survey

A joint project between the Interdept. Research Center of the University of Padova (CIRGEO), a research group of Istituto Tecnico per la Ricerca Scientifica e Tecnologica (IRST) of Trento and the Visual Information Technology group (VIT) of the NRC Canada, in Ottawa, has been undertaken, with the main aim to create a set of 3D models of an historical building by means of photogrammetry and laser scanning-based surveying techniques. Beside the investigation of their geometric accuracy, a photorealistic representation suited for interactive navigation and manipulation in VR environment was a further objective of thie project. To this aim, the main room in the Aquila tower in Buonconsiglio castle (Trento, Italy) was choosen, as it featured a relative simple geometry along with artistically and historically very precious frescoed walls. In this paper a description of both surveying and modeling procedures adopted and results of a comparison test between employed techniques are presented

Photo-Realistic 3D Reconstruction of Castles with Multiple Sources Image Based Techniques

Digitally reconstructing a large and complex heritage site, particularly medieval castles, for documentation, research, and virtual reality simulation is a challenging task. Castles by design contain many lines of defense such as inner and outer rings of walls and are often located on high grounds, surrounded by water or forests. They also have protective entrances, towers, courtyards, and a mixture of large complex buildings. Although laser scanners have many advantages, they may be impractical for reconstructing an entire castle. They are not portable or fast enough and can generate a huge amount of data that is difficult to register and visualize in real time. Therefore, we set out to fully explore the potential of only image-based techniques for modeling castles. We captured aerial and ground-based images and used existing floor plans and limited surveying, which compelled us to develop a technique to assemble and integrate models made from different data sets. We will discuss the issues and problems associated with modeling castles, give details of our approach, and present and evaluate the results of modeling the Stenico castle in Trentino, Italy, as a test-be

Visualization of Frescoed Surfaces: Buonconsiglio Castle - Aquila Tower, Cycle of the Months

One of the major masterpieces of international Gothic art (1350-1450) is located in the Aquila tower in Buonconsiglio castle, Trento, Italy. The main room in the tower is completely frescoed with the <em>Cycle of the Months</em>, a rare example of medieval painting on a nonreligious subject. The frescos depict medieval time month by month with stunning details of the landscape, costumes, and every element of daily life. As part of the PEACH (Personal Experience with Active Cultural Heritage) project, the objective of this work is to acquire the most suitable data and generate a textured 3D model for interactive manipulation and creation of a photo-realistic walkthrough movie. This will give a vista to scientists, conservationists, historians, and visitors for looking at and studying this room and its frescos in virtual reality. Since photo-realism of the frescos is of utmost importance, it became apparent that many issues related to geometric and radiometric distortions must be addressed. For example, texture data is typically collected as images containing specific lighting conditions. When these images are stitched together, discontinuities are usually visible. Another predicament is the real-time requirement of visualization and manipulation of 3D models. Since it is important to maintain the best texture quality to visualize the details of the frescos and at the same time have smooth interactive visualization, memory problems had to be addressed. We build upon existing techniques developed for texture acquisition and reconstruction to generate efficient maps of high visual quality. Results of the first phase of the project are presented.L'un des grands chefs-d'?uvre de l'art gothique international (1350-1450) se trouve dans la tour de l'Aquila du ch\ue2teau de Buonconsiglio, \ue0 Trente en Italie. Les murs de la salle principale de la tour sont enti\ue8rement couverts par les fresques du <em>Cycle des mois</em>, rare exemple de peinture m\ue9di\ue9vale sur un sujet non religieux. Les fresques d\ue9peignent l'\ue9poque m\ue9di\ue9vale, mois par mois, avec des d\ue9tails stup\ue9fiants du paysage, des costumes et de divers \ue9l\ue9ments de la vie de tous les jours. R\ue9alis\ue9 dans le cadre du projet PEACH (Personal Experience with Active Cultural Heritage [exp\ue9rience personnelle du patrimoine culturel actif]), le pr\ue9sent travail a pour objectif d'acqu\ue9rir les donn\ue9es les plus pertinentes et de g\ue9n\ue9rer un mod\ue8le tridimensionnel textur\ue9 en vue de la cr\ue9ation et de la manipulation interactive d'un film virtuel photo-r\ue9aliste, ce qui donnera une fen\ueatre aux scientifiques, aux restaurateurs, aux historiens et aux visiteurs d\ue9sireux de voir et d'\ue9tudier en r\ue9alit\ue9 virtuelle cette salle et les fresques qu'elle contient. Comme le photo-r\ue9alisme des fresques est d'une importance capitale, il est devenu manifeste qu'il faudrait se pencher sur de nombreuses questions li\ue9es aux distorsions g\ue9om\ue9triques et radiom\ue9triques. Par exemple, les donn\ue9es relatives \ue0 la texture sont normalement recueillies comme des images contenant des conditions pr\ue9cises d'\ue9clairage. C'est lorsque ces images sont jointes que les discontinuit\ue9s deviennent habituellement apparentes. Une autre limite est l'exigence de visualisation et de manipulation en temps r\ue9el des mod\ue8les tridimensionnels. Comme il est important de maintenir une qualit\ue9 sup\ue9rieure de texture pour visualiser les d\ue9tails des fresques et, en m\ueame temps, assurer une visualisation interactive sans heurt, il a fallu r\ue9gler des probl\ue8mes de m\ue9moire. Nous avons mis\ue9 sur des techniques mises au point pour l'acquisition et la reconstitution de la texture dans le but de g\ue9n\ue9rer des cartes efficientes d'une qualit\ue9 visuelle sup\ue9rieure. Le pr\ue9sent rapport donne les r\ue9sultats de la premi\ue8re phase du projet.NRC publication: Ye

Photo-Realistic 3D Reconstruction of Castles with Multiple-Sources Image-Based Techniques

Digitally reconstructing a large and complex heritage site, particularly medieval castles, for documentation, research, and virtual reality simulation is a challenging task. Castles by design contain many lines of defense such as inner and outer rings of walls and are often located on high grounds, surrounded by water or forests. They also have protective entrances, towers, courtyards, and a mixture of large complex buildings. Although laser scanners have many advantages, they may be impractical for reconstructing an entire castle. They are not portable or fast enough and can generate a huge amount of data that is difficult to register and visualize in real time. Therefore, we set out to fully explore the potential of only image-based techniques for modeling castles. We captured aerial and ground-based images and used existing floor plans and limited surveying, which compelled us to develop a technique to assemble and integrate models made from different data sets. We will discuss the issues and problems associated with modeling castles, give details of our approach, and present and evaluate the results of modeling the Stenico castle in Trentino, Italy, as a test-bed.La reconstruction num\ue9rique d'un grand site patrimonial complexe, et particuli\ue8rement des ch\ue2teaux m\ue9di\ue9vaux, \ue0 des fins de documentation, de recherche et de simulation en r\ue9alit\ue9 virtuelle, constitue un v\ue9ritable d\ue9fi. De par leur conception m\ueame, les ch\ue2teaux comportent plusieurs lignes de d\ue9fense comme des murs p\ue9riph\ue9riques int\ue9rieurs et ext\ue9rieurs, et ils sont souvent situ\ue9s en terrain \ue9lev\ue9, entour\ue9s d'eau ou de for\ueats. Ils comportent \ue9galement des entr\ue9es de protection, des tours, des cours et un m\ue9lange de grands b\ue2timents complexes. Bien que les scanners laser pr\ue9sentent de nombreux avantages, ils peuvent s'av\ue9rer peu pratiques pour la reconstruction d'un ch\ue2teau au complet. Ils ne sont pas portables ou suffisamment rapides, et peuvent g\ue9n\ue9rer un vaste volume de donn\ue9es qu'il est difficile d'enregistrer et de visualiser en temps r\ue9el. C'est pourquoi nous nous sommes propos\ue9s d'explorer int\ue9gralement le potentiel des techniques \ue0 base d'images seulement pour la mod\ue9lisation des ch\ue2teaux. Nous avons captur\ue9 des images a\ue9riennes et terrestres, nous nous sommes servis des plans d'\ue9tages existants et avons effectu\ue9 un arpentage restreint, ce qui nous a incit\ue9s \ue0 mettre au point une technique permettant d'assembler et d'int\ue9grer des mod\ue8les r\ue9alis\ue9s \ue0 partir d'ensembles de donn\ue9es diff\ue9rents. Nous examinerons les probl\ue8mes associ\ue9s \ue0 la mod\ue9lisation des ch\ue2teaux, fournirons des d\ue9tails sur notre approche, et pr\ue9senterons et \ue9valuerons les r\ue9sultats de la mod\ue9lisation du ch\ue2teau de Stenico \ue0 Trentino, en Italie, \ue0 titre de banc d'essai.NRC publication: Ye

Experience and Challenges in 3D Digital Documentation of Frescoed Walls and Ceilings from Images

In this paper we report on our experience in creating photo-realistic virtual environments of frescoed surfaces to allow scientists, conservationists, historians, and tourists to closely study important frescoes at high level of details. In addition to allowing unlimited virtual access, this will also protect the frescoes from the damage that can be caused by opening the site to a large number of visitors. We address the main challenges associated with photo-realism or texture quality, and real-time interactive visualization and discuss available solutions. Where no effective solutions existed, we had to develop our own techniques. As case studies, we present results of modeling and visualization of two sites, both located at Buonconsiglio castle, one of the most important castles in Trentino in northern Italy. The first is the frescoed walls \u201cCycle of the Months\u201d, a major masterpieces of international Gothic art that was painted around 1400. The second is the Gothic-Venetian Romanino loggia, named after the artist Girolamo Romanino (1484-1562) who decorated the ceiling and walls of the loggia, as well as the adjacent corridors, with remarkable frescoes in 1531.Dans cet article, nous rendons compte de notre exp\ue9rience dans la cr\ue9ation d'environnements virtuels photor\ue9alistes de surfaces de fresques, permettant aux scientifiques, \ue9cologistes, historiens et touristes d'\ue9tudier de pr\ue8s des fresques importantes avec un niveau de d\ue9tail \ue9lev\ue9. En plus d'un acc\ue8s virtuel illimit\ue9, cela permettra de prot\ue9ger les fresques contre tout dommage risquant d'\ueatre caus\ue9 par l'ouverture des projets \ue0 un grand nombre de visiteurs. Nous abordons les principaux enjeux associ\ue9s au photor\ue9alisme ou \ue0 la qualit\ue9 de la texture, et \ue0 la visualisation interactive en temps r\ue9el, et nous examinons les solutions possibles. Dans les cas o\uf9 il n'y avait aucune solution efficace, nous avons d\ue9velopp\ue9 nos propres techniques. Nous avons pr\ue9sent\ue9 sous forme d'\ue9tudes de cas les r\ue9sultats de la mod\ue9lisation et de la visualisation de deux lieux, tous deux dans le ch\ue2teau de Buonconsiglio, l'un des plus importants ch\ue2teaux du Trentin dans le nord de l'Italie. Le premier projet est les fresques murales du \uab Cycle des mois \ubb, un chef-d'\u153uvre majeur de l'art gothique international, qui a \ue9t\ue9 peint autour des ann\ue9es 1400. Le second est la loggia v\ue9nitienne gothique du Romanino, nomm\ue9e en souvenir de l'artiste Girolamo Romanino (1484-1562), qui a d\ue9cor\ue9 en 1531 le plafond et les murs de la loggia, ainsi que les corridors adjacents, avec des fresques remarquables.NRC publication: Ye

On the Digital Reconstruction and Interactive Presentation of Heritage Sites through Time

Virtual time travel from existing remains of a heritage site to its previous states and original condition is an educational and interesting experience and can provide better understanding of history. However, digitally reconstructing non-existing objects is a challenge. The interaction and navigation within virtual 4D worlds (adding time to 3D worlds) is also problematical due to the time dimension. In this paper we developed an approach to modelling of heritage sites that has undergone changes over the years. The method creates independent models from different types of data, such as frescos and paintings, drawings, old photos, historic descriptions, and digitization of remains, then assembles and integrates these models for an interactive presentation. Several research issues had to be addressed: (1) Modelling from frescos and drawings with incorrect perspective, (2) modelling from paintings and old photos including fine geometric details from shading (3) colouring models from old photos and drawings to match the colours of existing elements, (4) the seamless and accurate integration of models created independently from different sets of data, and (5) the creation of intuitive interactive presentation that combines all the models and other useful information. We provide contributions to these issues, including our own advanced model viewer, and apply them to modelling of: destroyed Haida house of Chief Weah (Masset, Canada), the demolished and partially relocated Rideau Chapel (Ottawa, Canada), and the Stenico castle (Trentino, Italy) which undergone many changes over several centuries. Each of these diverse examples illustrates different approach for reconstructing heritage sites that changed through time.Un voyage virtuel dans le temps, depuis les vestiges d'un site patrimonial vers ses \ue9tats ant\ue9rieurs et son \ue9tat initial, constitue une exp\ue9rience \ue9ducative int\ue9ressante et permet d'obtenir une meilleure compr\ue9hension de l'histoire. Toutefois, la reconstruction num\ue9rique d'objets inexistants repr\ue9sente un d\ue9fi. L'interaction et la navigation dans des mondes virtuels quadridimensionnels (le temps \ue9tant ajout\ue9 \ue0 des mondes tridimensionnels) sont \ue9galement probl\ue9matiques en raison de la dimension temporelle. Dans le pr\ue9sent article, nous avons \ue9labor\ue9 une approche \ue0 la mod\ue9lisation de sites patrimoniaux qui ont subi des modifications au cours des ann\ue9es. Notre m\ue9thode cr\ue9e d'abord des mod\ue8les ind\ue9pendants pour diff\ue9rents types de donn\ue9es, notamment des fresques et des peintures, des dessins, d'anciennes photos, des descriptions historiques et la num\ue9risation de vestiges, pour ensuite assembler et int\ue9grer ces mod\ue8les en une pr\ue9sentation interactive. Nous avons d\ufb r\ue9soudre plusieurs probl\ue8mes de recherche : (1) la mod\ue9lisation d'apr\ue8s des fresques et des dessins dont la perspective est inexacte, (2) la mod\ue9lisation d'apr\ue8s des peintures et d'anciennes photos comportant de fins d\ue9tails g\ue9om\ue9triques contenus dans les ombrages (3) la coloration des mod\ue8les d'apr\ue8s des photos et des dessins anciens de fa\ue7on \ue0 faire correspondre les couleurs aux \ue9l\ue9ments existants, (4) l'int\ue9gration uniforme et exacte de mod\ue8les cr\ue9\ue9s ind\ue9pendamment, d'apr\ue8s diff\ue9rents jeux de donn\ue9es, (5) l'\ue9laboration d'une pr\ue9sentation intuitive interactive qui combine tous les mod\ue8les et d'autres renseignements utiles. Nous apportons nos solutions \ue0 ces probl\ue8mes, notamment notre propre visionneuse perfectionn\ue9e de mod\ue8les, et nous les appliquons \ue0 la mod\ue9lisation de b\ue2timents, notamment : la maison ha\uefda d\ue9truite du chef Weah (Masset, Canada), la chapelle Rideau d\ue9molie et partiellement d\ue9m\ue9nag\ue9e (Ottawa, Canada) et le ch\ue2teau de Stenico (Trentin, Italie) souvent transform\ue9 au cours des si\ue8cles. Ces divers exemples illustrent une approche diff\ue9rente pour la reconstruction de sites patrimoniaux modifi\ue9s au fil du temps.NRC publication: Ye

3D Virtual Reconstruction and Visualization of Complex Architectures - The "3D-ARCH" Project

Peer reviewed: YesNRC publication: Ye