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Now showing 1 - 10 of 10
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    Visual Language Generalization for Procedural Modeling of Buildings
    (The Eurographics Association, 2012) Barroso, Santiago; Patow, Gustavo; Isabel Navazo and Gustavo Patow
    Procedural modeling has become the accepted standard for the creation of detailed large scenes, in particular urban landscapes. With the introduction of visual languages there has been a huge leap forward in terms of usability, but there is still need of more sophisticated tools to simplify the development process. In this paper we present extensions to the visual modeling of procedural buildings, which adapt concepts from general purpose programming languages, with the objective of providing higher descriptive power. In particular, we present the concepts of visual modules, parameter linking and the possibility to seamlessly add abstract parameter templates to the designer visual toolbox. We base our demonstrations on a new visual language created for volume-based models like historic architectonic structures (aqueducts, churches, cathedrals, etc.), which cannot be modeled as 2D facades because of the intrinsic volumetric structure of these construction (e.g. vaults or arches).
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    Tools for Structural Analysis and Optimization of Procedural Masonry Buildings
    (The Eurographics Association, 2016) Fita, Josep Lluis; Besuievsky, Gonzalo; Patow, Gustavo; Alejandro Garcia-Alonso and Belen Masia
    We present a set of off-the-shelf tools that will enable structural simulations and optimization into procedural modeled masonry buildings, as historical buildings like cathedrals or churches. For instance, with our tools we are capable of easily knowing whether the roof of a given masonry structure is sound, if it falls down, and, in the later case, even which brick of this structure has moved. For this we integrate a set of custom tools into the available Houdini platform [Sid12], together with the freely available Bullet engine and a set of Python scripts to quickly and efficiently simulate masonry structures.
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    Procedural Semantic Cities
    (The Eurographics Association, 2017) Rogla, Otger; Pelechano, Nuria; Patow, Gustavo; Fco. Javier Melero and Nuria Pelechano
    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.
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    A Procedural Modeling System for the Creation of Huge Models
    (The Eurographics Association, 2012) Cubero, Francisco; Mas, Albert; Patow, Gustavo; Isabel Navazo and Gustavo Patow
    This paper presents a new general purpose procedural geometrical modeling system. It is focused on providing flexibility, modularity and scalability. Furthermore, it is taylored to manage huge geometric models, with millions of polygons. An out-of-core memory management system assures that any scene size can be generated during the modeling evolution. This generation is performed by a set of rules and operations on geometrical objects, organized as a directed acyclic graph.
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    Knight Lore 20xx: Bringing a Classic Game to Modern Technology
    (The Eurographics Association, 2016) Galvany, Ricard; Patow, Gustavo; Alejandro Garcia-Alonso and Belen Masia
    This paper reports about the experience, problems encountered, and the solutions found to develop Knight Lore 20XX, an experiment of using Computer Graphics techniques to bring a classic game from the 80's to modern technology.
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    Simulation of the Commercial Market Evolution in a City
    (The Eurographics Association, 2015) Soriano, Carlos; Patow, Gustavo; Mateu Sbert and Jorge Lopez-Moreno
    Simulating the evolution of urban landscapes is a challenging objective with a large impact not only for Computer Graphics (for its applications in the filming and gaming industries), but also for urban planning, economical and historical studies, urban physics, and many other. However, this target has remained elusive because of the large complexity implied by urban structures and their evolutions. We present a system that aims at simulating the evolution of the commercial structure in a modern city. In particular, given an initial distribution of shops, it studies the evolution when larger commercial areas, like malls, are introduced. This is computed using the Huff model as a measure of the attraction each commerce has on potential consumers, and an agent-based simulation to determine how these aspects affect their choices. Then, after a given simulation time, the system decides whether the shop has retained an income such that it can continue operating, or has gone bankrupt. Our system is used to study the evolution of the commercial structure of Barcelona city over the last century. 1. Introduction Procedural urban modeling has presented us with astonishing results over the last decade, starting with the seminal work by Parish and Muller [PM01] and Muller et al. [MWH 06], and continuing with the recent advances in acquisition [MWA 12], non-regular modeling [LCOZ 11], user interfaces [Pat12], among others. However, in spite of all those improvements, several problems remain open [PBP14], one of the most important ones is simulating the evolution of urban landscapes over time. With only a few exceptions [WMWG09,BWK14], this topic has barely been touched, in spite of its crucial importance for history and archeology, urban planning, socio-economical studies, and many other social-related disciplines. Among these unexplored aspects, the problem of simulating the evolution of the commerce structure in a city is a prominent one, as it is attractive for being computationally tractable and crucial for socio-economic studies. But this study has applications that are broader than a pure social analysis, as the resulting distributions can be used to also model its appearance over time, which is interesting for computer graphics because of its applications to film and videogames, two of the leading industries in the field. y carlos.
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    An Interactive Tool for Modeling Ancient Masonry Buildings
    (The Eurographics Association, 2017) Fita, Josep Lluis; Besuievsky, Gonzalo; Patow, Gustavo; Fco. Javier Melero and Nuria Pelechano
    We present a new pipeline of an interactive tool that combines procedural modeling of ancient masonry buildings with structural simulation. The tool has been designed for taking an input geometry of an ancient building and re-meshing it into a suitable mesh with a low quad density. Then, it creates the brick outlines on the mesh and adds the brick volumes for structural simulation. The tool was designed and built on a set of off-the-shelf tools. We tested and demonstrated its viability by modeling of a Romanesque church based on a real one from the 11th century, such as the church of Santa Maria de Agullana.
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    Easy Going Vector Graphics as Textures on the GPU
    (The Eurographics Association, 2015) Patow, Gustavo; Mateu Sbert and Jorge Lopez-Moreno
    One common problem of raster images when used as textures is its resolution dependence, which could produce artifacts such as blurring. On the contrary, vector graphics are resolution independent, and their direct use for real-time texture mapping would be desirable to avoid sampling artifacts. Usually, they composite images from layers of paths and strokes defined with different kinds of lines. Here I present a simple yet powerful technique for representing vector graphics as textures that organizes the graphic into a coarse grid of cells, structuring each cell into simple cell-sized BSP trees, evaluated at runtime within a pixel shader. Advantages include coherent low-bandwidth memory access and, although my implementation is limited to polygonal shapes, the ability to map general vector graphics onto arbitrary surfaces. A fast construction algorithm is presented, and the space and time efficiency of the representation are demonstrated on many practical examples.
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    Bringing Direct Local Control to Interactive Visual Editing of Procedural Buildings
    (The Eurographics Association, 2012) Riu, Adria; Patow, Gustavo; Isabel Navazo and Gustavo Patow
    This paper presents a new system to add direct and persistent local control to the visual editing of rules for procedural buildings, avoiding a combinatorial explosion of grammar rules. In this paper we follow the ideas initially proposed by Lipp and co-workers [LWW08]. For this, we have added a few simple new commands, which are added to the artist-provided ruleset in a way completely transparent to the user. The end-user selects the primitives/assets to modify, and the system automatically incorporates these modifications into the ruleset. This change is performed using graph-rewriting techniques, which are both simple to define and control, but also very powerful and practical for these situations.
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    Fast Inverse Reflector Design (FIRD)
    (The Eurographics Association, 2008) Mas, Albert; Martin, Ignacio; Patow, Gustavo; Luis Matey and Juan Carlos Torres
    This paper presents a new method ofr a GPU-based computation of outgoing light distribution for inverse reflector design. We propose a fast method to obtain the outgoing light distribution of a parametrized reflector, and compare it with the desired illumination, that works completely in the GPU. We trace millions of rays using a hierarchical height-field representation of the reflector. Multiple reflections are taken into account. The parameters that define the reflector shape are optimized in an iterative procedure in order that the resulting light distribution is as close as possible to the user-provided target light distribution. We show that our method can calculate the reflector lighting at least one order of magnitude faster, even with millions of rays, and complex geometries and light sources.