Procedural modeling historical buildings for serious games

[EN] In this paper we target the goal of obtaining detailed historical virtual buildings, like a castle or a city old town, through a methodology that facilitates their reconstruction. We allow having in a short time an approximation model that is flexible for being explored, analyzed and eventually modified. This is crucial for serious game development pipelines, whose objective is focused not only on accuracy and realism, but also on transmitting a sense of immersion to the player.[ES] En este trabajo apuntamos al objetivo de obtener edificios históricos virtuales con alto nivel de detalle, como por ejemplo un castillo o un barrio de una ciudad antigua, a través de una metodología que facilite su reconstrucción. Las herramientas que proponemos nos permiten obtener rápidamente un modelo aproximado y flexible para ser explorado, analizado o eventualmente modificado. Modelos con estas características son esenciales para el desarrollo en plataformas de juegos serios, cuyo objetivo fundamental se centra no sólo en la precisión y el realismo, sino también en transmitir una sensación de inmersión para el jugador.We would like to thank Adriana Desplans for help with the Carcassonne prototype. This work was partially funded with grant TIN2010-20590-C02-02 from Ministerio de Ciencia e Innovación, Spain.Besuievsky, G.; Patow, G. (2013). Procedural modeling historical buildings for serious games. Virtual Archaeology Review. 4(9):160-166. https://doi.org/10.4995/var.2013.426816016649P. Müller, P. Wonka, S. Haegler, A. Ulmer, and L. Van Gool. Procedural modeling of buildings. ACM Trans. Graph., 25(3):614-623, 2006. http://dx.doi.org/10.1145/1141911.1141931P.Musialski, P. Wonka, D. Aliaga, M. Wimmer, L. van Gool and W. Purgathofer. A Survey of Urban Reconstruction. EUROGRAPHICS 2012 State of the Art ReportsS. Haegler, P.Mller and L. Van Gool. Procedural Modeling for Digital Cultural Heritage. EURASIP J. Image and Video Processing V 2009.R. Ridorsa, G. Patow, The skylineEngine System, in XX Congreso Español de Iinformàtica Gràfica, CEIG2010 (2010), pp. 207-216L. Krecklau, C. Manthei, L. Kobbelt. Procedural Interpolation of Historical City Maps. Vol. 31 (2012), Number 2G. Patow, User-Friendly Graph Editing for Procedural Buildings.IEEE Computer Graphics and Applications, vol. 32, no. 2, Mar./Apr. 2012, pp. 66--75; http://dx.doi.org/10.1109/MCG.2010.104B.Watson, P. Müller, O. VERYOVKA, A.Filler., P. Wonka and C.Sexton. 2008. Procedural urban modeling in practice. IEEE Computer Graphics and Applications 28, 18-26. http://dx.doi.org/10.1109/MCG.2008.57CityEngine 2011. www.procedural.comG. Besuievsky and G. Patow, A Procedural Modelling Approach for Automatic Generation of LoD Building Models, Proceedings of the CISBAT 2011, pp. 993-998, Lausanne, Switzerland.O. Pueyo, G. Patow. Structuring Urban Data, Tech. Rep. IMA12-01-RR, Dept. IMA, Universitat de Girona (2012)S.Barroso, G.Patow. Recreación de estructuras arquitectónicas mediante modelaje

On Improving Urban Environment Representations

Computer Graphics has evolved into a mature and powerful field that offers many opportunities to enhance different disciplines, adapting to the specific needs of each. One of these important fields is the design and analysis of Urban Environments. In this article we try to offer a perspective of one of the sectors identified in Urban Environment studies: Urbanization. More precisely we focus on geometric and appearance modeling, rendering and simulation tools to help stakeholders in key decision stages of the process

A PERSPECTIVE ON PROCEDURAL MODELING BASED ON STRUCTURAL ANALYSIS

[EN] We introduce a study focused on procedural modeling papers that use methods of structural analysis, especially in its application to historic buildings such as churches and cathedrals. Moreover, we have taken a geometric structure of one of these papers and studied their behavior in a generic simulation tool, thus showing the feasibility of its analysis with non-specialized tools.[ES] Introducimos un estudio centrado en aquellos trabajos de modelado procedural que utilizan métodos de análisis estructural, especialmente en su aplicación para edificios históricos como iglesias y catedrales. Por otra parte, hemos tomado una estructura geométrica de uno de estos artículos y estudiado su comportamiento en una herramienta de simulación genérica, mostrando su factibilidad para realizar análisis con herramientas no especializadas.Fita, JL.; Besuievsky, G.; Patow, GA. (2016). A PERSPECTIVE ON PROCEDURAL MODELING BASED ON STRUCTURAL ANALYSIS. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 264-266. https://doi.org/10.4995/arqueologica8.2015.304526426

A Comprehensive Method for Liquid-to-Solid Interactions

Realistic real-time water-solid interaction has been an open problem in Computer Graphics since its beginnings, mainly due to the complex interactions that happen at the interface between solid objects and liquids, both when objects are completely or partially wet, or when they are fully submerged. In this paper we present a method that tackles the two main aspects of this problem, namely the buoyancy of objects submerged into fluids, and the superficial liquid propagation and appearance changes that arise at the interface between the surface of solid objects in contact with a liquid. For the first problem (buoyancy) a method is proposed to realistically compute the fluid-to-solid coupling problem. Our proposal is suitable for a wide spectrum of cases, such as rigid or deformable objects, hollow or filled, permeable or impermeable, and with variable mass distribution. In the case of permeable materials, which allow liquid to pass through the object, the presented method incorporates the dynamics of the fluid in which the object is submerged, and decouples the computation of the physical quantities involved in the buoyancy force of the empty object with respect to to the liquid contained within it. On the other hand, the visual appearance of certain materials depends on their intrinsic light transfer properties, the lighting present and other environmental contributions. Thus, complementing the first approach in this paper, a new technique is introduced to model and render the appearance changes of absorbent materials when there is liquid on their surface. Also, a new method was developed to solve the problem of the interaction between the object surface and liquids, taking advantage of texture coordinates. An algorithm was proposed to model the main physical processes that occur on the surface of a wet or wet solid object. Finally, we model the change in appearance that typically arise in most materials in contact with fluids, and an algorithm is implemented achieving real-time performance. The complete solution is designed taking advantage of superscalar architectures and GPU acceleration, allowing a flexible integration with the pipelines of current graphic engines.Fil: Bajo, Juan Miguel. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Delrieux, Claudio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Patow, Gustavo. No especifíca

Recreation of architectural structures using procedural modeling based on volumes

[ES] Si bien el modelado procedural de edificios y otras estructuras arquitectónicas ha evolucionado de manera muy significativa en los últimos años, existe una notable ausencia de herramientas de alto nivel que permitan a un diseñador, un artista o un historiador, crear edificios o estructuras arquitectónicasimportantes de alguna ciudad en particular. En este trabajo presentaremos una herramienta para la creación de este tipo de edificios de manera simple y clara, siguiendo reglas que utilicen el lenguaje y metodología de creación propios de los edificios, y ocultando al usuario los detalles algorítmicos de lacreación del modelo.[EN] While the procedural modeling of buildings and other architectural structures has evolved very significantly in recent years, there is noticeable absence of high-level tools that allow a designer, an artist or an historian, creating important buildings or architectonic structures in a particular city. In this paper we present a tool for creating buildings in a simple and clear, following rules that use the language and methodology of creating their own buildings, and hiding the user the algorithmic details of the creation of the model.Queremos agradecer a Emily Whiting por los ejemplos que nos facilitó, así como a todos los miembros del Grup de Geometriai Gràfics de la Universitat de Girona por toda su ayuda. Este proyecto fue parcialmente financiado con el proyecto TIN2010-20590-C02-02 del Ministerio de Ciencia e Innovación.Barroso Juan, S.; Patow, G. (2013). Recreación de estructuras arquitectónicas mediante modelaje procedural basado en volúmenes. Virtual Archaeology Review. 4(9):76-81. https://doi.org/10.4995/var.2013.4251OJS768149P. Wonka, M. Wimmer, F. Sillion, and W. Ribarsky. Instant architecture. ACM Transaction on Graphics, 22(3):669-677, July 2003. Proceedings ACM SIGGRAPH 2003. 10. http://dx.doi.org/10.1145/1201775.882324P. Müller, P. Wonka, S. Haegler A. Ulmer, and L. Van Gool. Procedural modeling of buildings. ACM Trans. Graph., 25 (3):614-623, 2006. http://dx.doi.org/10.1145/1141911.1141931G. Patow, User-Friendly Graph Editing for Procedural Buildings. IEEE Computer Graphics and Applications, vol. 32, no. 2, Mar./Apr. 2012, pp. 66-75; doi:10.1109/MCG.2010.104. http://dx.doi.org/10.1109/MCG.2010.104E. Whiting, J. Ochendorf, F. Durand, Procedural modeling of structurally-sound masonry buildings. ACMSIGGRAPH Asia 2009 papers (New York, NY, USA, 2009), SIGGRAPH Asia '09, ACM, pp. 112:1-112

Procedural semantic cities

Procedural modeling of virtual cities has achieved high levels of realism with little effort from the user. One can rapidly obtain a large city using off-the-shelf software based on procedural techniques, such as the use of CGA. However in order to obtain realistic virtual cities it is necessary to include virtual humanoids that behave realistically adapting to such environment. The first step towards achieving this goal requires tagging the environment with semantics, which is a time consuming task usually done by hand. In this paper we propose a framework to rapidly generate virtual cities with semantics that can be used to drive the behavior of the virtual pedestrians. Ideally, the user would like to have some freedom between fully automatic generation and usage of pre-existing data. Existing data can be useful for two reasons: re-usability, and copying real cities fully or partly to develop virtual environments. In this paper we propose a framework to create such semantically augmented cities from either a fully procedural method, or using data from OpenStreetMap. Our framework has been integrated with Unreal Engine 4.Peer ReviewedPostprint (published version

Procedural modeling buildings for finite element method simulation

Finite element methods for heat simulation at urban scale require mesh-volume models, where the meshing process requires a special attention in order to satisfy FEM requirements. In this paper we propose a procedural volume modeling approach for automatic creation of mesh-volume buildings, which are suitable for FEM simulations at urban scale. We develop a basic rule-set library and a building generation procedure that guarantee conforming meshes. In this way, urban models can be easily built for energy analysis. Our test-case shows a street created with building prototypes that fulfill all the requirements for being loaded in a FEM numerical platform such as Cast3M (www-cast3m.cea.fr).Postprint (published version

Una perspectiva sobre el modelado procedural basado en análisis estructurales

[EN] With the rise of available computing capabilities, structural analysis has recently become a key tool for building assessment usually managed by art historians, curators, and other specialist related to the study and preservation of ancient buildings. On the other hand, the flourishing field of procedural modeling has provided some exciting breakthroughs for the recreation of lost buildings and urban structures. However, there is a surprising lack of literature to enable the production of procedural-based buildings taking into account structural analysis, which has proven to be a crucial element for the recreation of faithful masonry structures. In order to perform an in-depth study of the advances in this type of analysis for cultural heritage buildings, we performed a study focused on procedural modeling that make use of structural analysis methods, especially in its application to historic masonry buildings such as churches and cathedrals. Moreover, with the aim of improving the knowledge about structural analysis of procedurally-recreated historical buildings, we have taken a geometric structure, added a set of procedural walls structured in masonry bricks, and studied its behavior in a generic, freely-available simulation tool, thus showing the feasibility of its analysis with non-specialized tools. This not only has allowed us to understand and learn how the different parameter values of a masonry structure can affect the results of the simulation, but also has proven that this kind of simulations can be easily integrated in an off-the-shelf procedural modeling tool, enabling this kind of analysis for a wide variety of historical studies, or restoration and preservation actions.[ES] Con el creciente aumento de las capacidades computacionales, el análisis estructural se ha convertido en una herramienta clave para la evaluación del estudio y conservación de edificios antiguos por parte de los historiadores del arte, curadores y otros especialistas. Por otro lado, el floreciente campo del modelado procedural ha proporcionado avances interesantes para la reconstrucción de edificios y estructuras urbanas no accesibles. Sin embargo, hay una sorprendente falta de métodos que permiten la generación deedificios procedurales, teniendo en cuenta el análisis estructural, los cuales handemostrado ser un elemento crucial para la concepciónde estructuras de mampostería. Con el fin de realizar un estudio en profundidad de los avances en este tipo de análisis para edificios del patrimonio cultural, se realizó un estudio centrado en elroldelmodelado proceduralque realizanmétodos de análisis estructural, especialmente en su aplicación a los edificios históricos de albañilería, tales como iglesias y catedrales. Por otra parte, con el objetivo de mejorar el conocimiento sobre el análisis estructural de los edificios históricos concebidosproceduralmente, hemos tomado una estructura geométrica de un atrículo, añadidoun conjunto de paredesproceduralesestructuradasen ladrillos, y estudiado su comportamiento conuna herramienta de simulación de pública disponibilidad.Con esto sedemuestra la viabilidad de su análisis con herramientas no especializadas. Esto no sólo nos ha permitido entender y aprender cómo los diferentes valores de los parámetros de una estructura de mampostería pueden afectar los resultados de la simulación, sino tambiénque este tipo de simulaciones se puede integrar fácilmente en una herramienta de modelado proceduralal alcance de todo público, lo que permite acercar este tipo de análisis a una amplia variedad de estudios históricos o acciones de restauración y conservación.This work was partially funded by the TIN2014-52211-C2-2-R project from Ministerio de Economia y Competividad, Spain.Fita, JL.; Besuievsky, G.; Patow, G. (2017). A perspective on procedural modeling based on structural analysis. Virtual Archaeology Review. 8(16):44-50. https://doi.org/10.4995/var.2017.5765SWORD445081

Estructuras geométricas jerárquicas para la modelización de escenas 3d

This work surveys on the principal hierarchical geometric structures used to represent 3D scenes. We also present the basic algorithms to work with them, an overview on some recent works and a comparative discussion. This work has been the outcomes of the graduate course "Estructuras geometricas jerarquicas" given within the Software Phd. program at Software Department of this university

Binary visual imagery discriminator from EEG signals based on convolutional neural networks

[EN] A Brain-Computer Intarface (BCI) is a technology that allows direct communication between the brain and the outside world without the need to use the peripheral nervous system. Most BCI systems focus on the use of motor imagination, evoked potentials, or slow cortical rhythms. In this work, the possibility of using visual imagination to construct a binary discriminator has been studied. EEG signals from seven people have been recorded while imagining seven geometric figures. Using convolutional neural networks it has been possible to distinguish between the imagination of a geometric figure and relaxation with an average success rate of 91 % with a Cohen kappa value of 0.77 and a percentage of false positives of 9 %.[ES] Las interfaces cerebro-máquina (Brain-Computer Intarface, BCI, en inglés) son una tecnología que permite la comunicación directa entre el cerebro y el mundo exterior sin necesidad de utilizar el sistema nervioso periferico. La mayoría de sistemas BCI se centran en la utilización de la imaginación motora, los potenciales evocados o los ritmos corticales lentos. En este trabajo se ha estudiado la posibilidad de utilizar la imaginación visual para construir un discriminador binario (brain-switch, en inglés). Concretamente, a partir del registro de señales EEG de siete personas mientras imaginaban siete figuras geométricas, se ha desarrollado un BCI basado en redes neuronales convolucionales y en la densidad de potencia espectral en la banda α (8-12 Hz), que ha conseguido distinguir entre la imaginación de una figura geométrica cualquiera y el relax, con un acierto promedio del 91 %, con un valor Kappa de Cohen de 0.77 y un porcentaje de falsos positivos del 9 %.Este trabajo ha sido parcialmente financiado por el proyecto TIN2017-88515-C2-2-R del Ministerio de Economía y Competitividad.Llorella, FR.; Iáñez, E.; Azorín, JM.; Patow, G. (2021). Discriminador binario de imaginación visual a partir de señales EEG basado en redes neuronales convolucionales. Revista Iberoamericana de Automática e Informática industrial. 19(1):108-116. https://doi.org/10.4995/riai.2021.14987OJS108116191Abhiram, Singh, A., Gumaste, 2019. Decoding imagined speech and computer control using brain waves. arXiv.Aggarwal, S., Chugh, N., Jan. 2019. Signal processing techniques for motor imagery brain computer interface: A review. Array 1-2, 100003. https://doi.org/10.1016/j.array.2019.100003Ahn, M., Lee, M., Choi, J., Jun, S., Aug. 2014. A review of brain-computer interface games and an opinion survey from researchers, developers and users. Sensors 14 (8), 14601-14633. https://doi.org/10.3390/s140814601Altman, D. G., 2006. Practical Statistics for Medical Research. Chapman & Hall/CRC.Anderson, C. W., Sijercic, Z., 1996. Classification of eeg signals from four subjects during five mental tasks. 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