Inspecció inmersiva de la reconstruccó virtual de la portalada del monestir de Ripoll

L'objectiu global d'aquest projecte és, partint d'una representació virtual de la portalada de Ripoll, realitzar-ne la inspecció immersiva. D'aquest objectiu global se'n deriven tres de ben diferents: • Visualització: Tenint en compte que el navegador havia d'estar en un museu, necessitavem una visualització el maxim de realista possible de la portalada. S 'ha de tenir en com pte pero que un deIs requeriments imposats pel MNAC era que havia de funcionar en un PC normal i corrent. Entre els requeriments imposats també s'hi trobava el permetre als usuaris accedir a diferents modes de funcionament, així dones es defineixen els següents modes d'interacció: - Mode navegació: Aquest és el mode estandard de navegació. Segueix la metafora de la grua en que l'usuari es pot moure en horitzontal i vertical com si estigués pujat a una grua. També es pot acostar i allunyar de la portalada i girar sobre el punt de la superfície que estiguem lnirant per tal de permetre'n la inspecció detallada des de qualsevol angle. Mode iHuminació solar: En aquest mode l'usuari pot canviar el dia i la hora de l'any en que s'observa la portalada. Mode d'informació: En aquest mode apareixen un seguit de punts, que la gent del MNAC havia introdult abans, amb informació rellevant sobre cada un deIs punts que s'estaven veient. - Mode demostració: Aquest mode és un mode de funcionament autonom en que es realitza un recorregut prefixat per alguns detalls de la portalada . • Interacció mitjançant una pantalla tactil: El visualitzador ha de comunicar-se amb un ordinador al que hi ha connectat una pantalla tactil per tal de permetre la interacció amb els usuaris. En la pantalla tactil s'introdueixen les interaccions que l'usuari vol realitzar i aquestes es transmeten al visualitzador que les interpreta i n'ajusta la visualització correctament . • Interacció implícita mitjan~ant un sistema de tracking: El visualitzador ha de permetre la interacció implícita a través d'un sistema de tracking i el moviment de l'usuari. Aquest sistema només permet el mode de navegació, és a dir ellTIOviment en els tres eixos i el canvi d'orientació. Aquest objectiu es realitza en dates posteriors a l'exposició com a experiment en el Centre de Realitat Virtual

Real time city visualization

The visualization of cities in real time has a lot of potential applications, from urban and emergency planning, to driving simulators and entertainment. The massive amount of data and the computational requirements needed to render an entire city in detail are the reason why a lot of techniques have been proposed in this eld. Procedural city generation, building simpli cation and visibility processing are some of the approaches used to solve a small subset of the problems that these applications need to face. Our work proposes a new city rendering algorithm that is a radically di erent approach to what has been done before in this eld. The proposed technique is based on a structuration of the city data in a regular grid which is traversed, at runtime, by a ray tracing algorithm that keeps track of visible parts of the scene. As a preprocess, a set of quads de ning the buildings of a city is transformed to the regular grid used by our algorithm. The rendering algorithm uses this data to generate a real time representation of the city minimizing the overdraw, a common problem in other techniques. This is done by means of a geometry shader to generate only the minimum number of fragments needed to render the city from a given position

Interactive inspection of complex multi-object industrial assemblies

The final publication is available at Springer via http://dx.doi.org/10.1016/j.cad.2016.06.005The use of virtual prototypes and digital models containing thousands of individual objects is commonplace in complex industrial applications like the cooperative design of huge ships. Designers are interested in selecting and editing specific sets of objects during the interactive inspection sessions. This is however not supported by standard visualization systems for huge models. In this paper we discuss in detail the concept of rendering front in multiresolution trees, their properties and the algorithms that construct the hierarchy and efficiently render it, applied to very complex CAD models, so that the model structure and the identities of objects are preserved. We also propose an algorithm for the interactive inspection of huge models which uses a rendering budget and supports selection of individual objects and sets of objects, displacement of the selected objects and real-time collision detection during these displacements. Our solution–based on the analysis of several existing view-dependent visualization schemes–uses a Hybrid Multiresolution Tree that mixes layers of exact geometry, simplified models and impostors, together with a time-critical, view-dependent algorithm and a Constrained Front. The algorithm has been successfully tested in real industrial environments; the models involved are presented and discussed in the paper.Peer ReviewedPostprint (author's final draft

La realidad virtual en el aprendizaje de historia mediante la interacción con humanoides virtuales

La realidad virtual ofrece la posibilidad de interactuar de manera inmersiva en mundos virtuales 3D. Estos mundos virtuales pueden ser representaciones de otros momentos históricos que permiten al usuario explorar los modelos virtuales como si de una visita turística al pasado se tratase. En este proyecto se ha realizado una reconstrucción virtual de la antigua ciudad romana de Tarragona (Tarraco) para ofrecer un entorno interactivo en el que los visitantes a la exposición puedan navegar por diferentes partes de la ciudad así como interactuar con humanoides virtuales representando romanos que ayudarán al usuario a recopilar información histórica y aprender mediante un sencillo juego interactivo.Peer ReviewedPostprint (author’s final draft

Inspecció inmersiva de la reconstruccó virtual de la portalada del monestir de Ripoll

L'objectiu global d'aquest projecte és, partint d'una representació virtual de la portalada de Ripoll, realitzar-ne la inspecció immersiva. D'aquest objectiu global se'n deriven tres de ben diferents: • Visualització: Tenint en compte que el navegador havia d'estar en un museu, necessitavem una visualització el maxim de realista possible de la portalada. S 'ha de tenir en com pte pero que un deIs requeriments imposats pel MNAC era que havia de funcionar en un PC normal i corrent. Entre els requeriments imposats també s'hi trobava el permetre als usuaris accedir a diferents modes de funcionament, així dones es defineixen els següents modes d'interacció: - Mode navegació: Aquest és el mode estandard de navegació. Segueix la metafora de la grua en que l'usuari es pot moure en horitzontal i vertical com si estigués pujat a una grua. També es pot acostar i allunyar de la portalada i girar sobre el punt de la superfície que estiguem lnirant per tal de permetre'n la inspecció detallada des de qualsevol angle. Mode iHuminació solar: En aquest mode l'usuari pot canviar el dia i la hora de l'any en que s'observa la portalada. Mode d'informació: En aquest mode apareixen un seguit de punts, que la gent del MNAC havia introdult abans, amb informació rellevant sobre cada un deIs punts que s'estaven veient. - Mode demostració: Aquest mode és un mode de funcionament autonom en que es realitza un recorregut prefixat per alguns detalls de la portalada . • Interacció mitjançant una pantalla tactil: El visualitzador ha de comunicar-se amb un ordinador al que hi ha connectat una pantalla tactil per tal de permetre la interacció amb els usuaris. En la pantalla tactil s'introdueixen les interaccions que l'usuari vol realitzar i aquestes es transmeten al visualitzador que les interpreta i n'ajusta la visualització correctament . • Interacció implícita mitjan~ant un sistema de tracking: El visualitzador ha de permetre la interacció implícita a través d'un sistema de tracking i el moviment de l'usuari. Aquest sistema només permet el mode de navegació, és a dir ellTIOviment en els tres eixos i el canvi d'orientació. Aquest objectiu es realitza en dates posteriors a l'exposició com a experiment en el Centre de Realitat Virtual

Real time city visualization

The visualization of cities in real time has a lot of potential applications, from urban and emergency planning, to driving simulators and entertainment. The massive amount of data and the computational requirements needed to render an entire city in detail are the reason why a lot of techniques have been proposed in this eld. Procedural city generation, building simpli cation and visibility processing are some of the approaches used to solve a small subset of the problems that these applications need to face. Our work proposes a new city rendering algorithm that is a radically di erent approach to what has been done before in this eld. The proposed technique is based on a structuration of the city data in a regular grid which is traversed, at runtime, by a ray tracing algorithm that keeps track of visible parts of the scene. As a preprocess, a set of quads de ning the buildings of a city is transformed to the regular grid used by our algorithm. The rendering algorithm uses this data to generate a real time representation of the city minimizing the overdraw, a common problem in other techniques. This is done by means of a geometry shader to generate only the minimum number of fragments needed to render the city from a given position

Real time city visualization

The visualization of cities in real time has a lot of potential applications, from urban and emergency planning, to driving simulators and entertainment. The massive amount of data and the computational requirements needed to render an entire city in detail are the reason why a lot of techniques have been proposed in this eld. Procedural city generation, building simpli cation and visibility processing are some of the approaches used to solve a small subset of the problems that these applications need to face. Our work proposes a new city rendering algorithm that is a radically di erent approach to what has been done before in this eld. The proposed technique is based on a structuration of the city data in a regular grid which is traversed, at runtime, by a ray tracing algorithm that keeps track of visible parts of the scene. As a preprocess, a set of quads de ning the buildings of a city is transformed to the regular grid used by our algorithm. The rendering algorithm uses this data to generate a real time representation of the city minimizing the overdraw, a common problem in other techniques. This is done by means of a geometry shader to generate only the minimum number of fragments needed to render the city from a given position

Real-time exploration of the virtual reconstruction of the entrance of the Ripoll Monastery

This paper presents the project of the virtual reconstruction and inspection of the "Portalada", the entrance of the Ripoll Monastery. In a first step, the monument of 7 x 11 meters was acquired using triangulation laser scanning technology, producing a dataset of more than 2000 range maps for a total of more than one billion triangles. After alignment and registration, a nearly complete digital model with 173M triangles and a sampling density of the order of one millimeter was produced and repaired. The paper describes the model acquisition and construction, the use of specific scalable algorithms for model repair and simplification, and then focuses on the design of a hierarchical data structure for data managing and view-dependent navigation of this huge dataset on a PC. Finally, the paper describes the setup for a usable, user-friendly and immersive system that induces a presence perception in the visitors.Peer ReviewedPostprint (published version

Depth map repairing for building reconstruction

This is the accepted version of the article which has been published in final form at https://diglib.eg.org/handle/10.2312/ceig20181162. This article may be used for non-commercial purposes in accordance with the Wiley Self-Archiving Policy [http://olabout.wiley.com/WileyCDA/Section/id-820227.html].Structure-from-motion along with multi-view stereo techniques jointly allow for the inexpensive scanning of 3D objects (e.g. buildings) using just a collection of images taken from commodity cameras. Despite major advances in these fields, a major limitation of dense reconstruction algorithms is that correct depth/normal values are not recovered on specular surfaces (e.g. windows) and parts lacking image features (e.g. flat, textureless parts of the facade). Since these reflective properties are inherent to the surface being acquired, images from different viewpoints hardly contribute to solve this problem. In this paper we present a simple method for detecting, classifying and filling non-valid data regions in depth maps produced by dense stereo algorithms. Triangles meshes reconstructed from our repaired depth maps exhibit much higher quality than those produced by state-of-the-art reconstruction algorithms like Screened Poisson-based techniques.Peer ReviewedPostprint (author's final draft

Real-time exploration of the virtual reconstruction of the entrance of the Ripoll Monastery

This paper presents the project of the virtual reconstruction and inspection of the "Portalada", the entrance of the Ripoll Monastery. In a first step, the monument of 7 x 11 meters was acquired using triangulation laser scanning technology, producing a dataset of more than 2000 range maps for a total of more than one billion triangles. After alignment and registration, a nearly complete digital model with 173M triangles and a sampling density of the order of one millimeter was produced and repaired. The paper describes the model acquisition and construction, the use of specific scalable algorithms for model repair and simplification, and then focuses on the design of a hierarchical data structure for data managing and view-dependent navigation of this huge dataset on a PC. Finally, the paper describes the setup for a usable, user-friendly and immersive system that induces a presence perception in the visitors.Peer Reviewe