Now showing items 1-20 of 59

  • 3D model deformations with arbitrary control points 

    Cerveró Abelló, Maria Àngels; Vinacua Pla, Álvaro; Brunet Crosa, Pere (2016-06-01)
    Article
    Restricted access - publisher's policy
    Cage-based space deformations are often used to edit and animate images and geometric models. The deformations of the cage are easily transferred to the model by recomputing fixed convex combinations of the vertices of the ...
  • A critical analysis of human-subject experiments in virtual reality and 3D user interfaces 

    Andújar Gran, Carlos Antonio; Brunet Crosa, Pere (Springer International Publishing, 2015)
    Part of book or chapter of book
    Restricted access - publisher's policy
    This paper is about the major peculiarities and difficulties we encounter when trying to validate research results in fields such as virtual reality (VR) and 3D user interfaces (3DUI). We review the steps in the empirical ...
  • A Geometric relaxation solver for parametric constraint-based models 

    Solano Albajés, Lluís; Brunet Crosa, Pere (1998-06)
    External research report
    Open Access
    In this paper, a new relaxation algorithm for solving geometric constraint-based models is proposed. The algorithm starts from a constructive symbolic representation of objects (Constructive ...
  • A parametric-space-based scan-line algorithm for rendering of bicubic surfaces 

    Pueyo Sánchez, Xavier; Brunet Crosa, Pere (1987)
    Article
    Open Access
    A novel scan-line algorithm for displaying bicubic surfaces is presented. Patches are decomposed on regions of constant sign of the z component of the normal before the scan process. Most of the computations are done in ...
  • A topological comparison of surface extraction algorithms 

    Andújar Gran, Carlos Antonio; Brunet Crosa, Pere; Fairén González, Marta; Navazo Álvaro, Isabel; Vinacua Pla, Álvaro (2006-01)
    External research report
    Open Access
    In many application areas, it is useful to convert the discrete information stored in the nodes of a regular grid into a continuous boundary model. Isosurface extraction algorithms di er on how the discrete information in ...
  • A Virtual Reality approach to progressive lenses simulation 

    Rodríguez Celaya, José Antonio; Brunet Crosa, Pere; Ezquerra, Norberto; Palomar, J.E. (2005)
    Conference report
    Restricted access - publisher's policy
    Progressive lenses are lenses that allow focusing objects at any distance. The main problem of these lenses is the arise of marginal zones that present aberrations in which vision is defective. The interest of our research ...
  • Affordable immersive projection system for 3d interaction 

    Andújar Gran, Carlos Antonio; Fairén González, Marta; Brunet Crosa, Pere (SIACG, 2002)
    Conference report
    Open Access
    This paper describes an affordable Virtual Reality system designed and developed by a group of researchers at the Polytechnic University of Catalunya (UPC). The system allows direct selection and manipulation of virtual ...
  • Algunas posibilidades y limitaciones de las técnicas de filtraje no lineal 

    Brunet Crosa, Pere; Pagès Fita, Jaume (Universitat Politècnica de Barcelona. Centre de Càlcul, 1978-09)
    Article
    Open Access
    El filtraje no lineal es una técnica con grandes posibilidades; previsiblemente podrá utilizarse para problemas tales como el de previsión, estudio de series cronológicas y estimación de parámetros. Cabe distinguir entre ...
  • Analysis of methods for generating octree models of objects from their silhouettes 

    Franquesa Niubó, Marta; Brunet Crosa, Pere (1997-01)
    Article
    Restricted access - publisher's policy
    Reconstructing 3D models from their projection images has been an interesting research topic in computer vision and geometric modeling. In this paper, we review several methods that generate octree models of objects from ...
  • Approximation of a variable density cloud of points by shrinking a discrete membrane 

    Esteve Cusiné, Jordi; Brunet Crosa, Pere; Vinacua Pla, Álvaro (North Holland, 2005-12)
    Article
    Restricted access - publisher's policy
    This paper describes a method to obtain a closed surface that approximates a general 3D data point set with nonuniform density. Aside from the positions of the initial data points, no other information is used. Particularly, ...
  • Biharmonic fields and mesh completion 

    Argudo Medrano, Óscar; Brunet Crosa, Pere; Chica Calaf, Antonio; Vinacua Pla, Álvaro (2015-11)
    Article
    Restricted access - publisher's policy
    We discuss bi-harmonic fields which approximate signed distance fields. We conclude that the bi-harmonic field approximation can be a powerful tool for mesh completion in general and complex cases. We present an adaptive, ...
  • Collision prediction using MKtrees 

    Franquesa Niubó, Marta; Brunet Crosa, Pere (2004)
    Conference report
    Restricted access - publisher's policy
    K dimensional tree data structure(Multiresolution Kdtree, MKtree) is introduced. In a complex scene containing a high number of individual objects, the MKtree represents a hierarchical subdivision of the scene objects that ...
  • Computer graphics at the Universitat Politècnica de Catalunya 

    Brunet Crosa, Pere; Joan Arinyo, Robert; Navazo Álvaro, Isabel; Tost Pardell, Daniela; Vila, S (1995-06)
    Article
    Restricted access - publisher's policy
    This paper describes the authors experience in the organization and teaching of courses of Computer Graphics for both undergraduate and graduate students. Curriculum contents and teaching methodologies are discussed, taking ...
  • Computing maximal tiles and application to impostor-based simplification 

    Andújar Gran, Carlos Antonio; Brunet Crosa, Pere; Chica Calaf, Antonio; Navazo Álvaro, Isabel; Rossignac, Jarek; Vinacua Pla, Álvaro (North Holland, 2004-08)
    Article
    Restricted access - publisher's policy
    The computation of the largest planar region approximating a 3D object is an important problem with wide applications in modeling and rendering. Given a voxelization of the 3D object, we propose an efficient algorithm to ...
  • Construcció de superfícies mitjançant funcions spline 

    Brunet Crosa, Pere (Universitat Politècnica de Barcelona. Centre de Càlcul, 1981-06)
    Article
    Open Access
    La contrucción de una superficie que interpole un conjunto de puntos dados con unos ciertos requisitos de suavidad y continuidad es un problema de gran importancia tanto en aplicaciones de diseño gráfico como en el ...
  • Data structures and algorithms for navigation in highly polygon-populated scenes 

    Saona Vázquez, Carlos Luis; Navazo Álvaro, Isabel; Brunet Crosa, Pere (1998-10)
    External research report
    Open Access
    We present the visibility octree, a new data structure to accelerate 3D navigation through very complex scenes. Our approach employs a conservative visibility technique to compute an approximation to the visibility space ...
  • Directional adaptive surface triangulation 

    Vigo Anglada, Marc; Pla García, Núria; Brunet Crosa, Pere (1999-02)
    Article
    Restricted access - publisher's policy
    Several CAD applications require a surface model of the modeled object consisting of a mesh of triangular facets. In this paper, a new algorithm for triangulation of trimmed surfaces is presented. The algorithm generates ...
  • Estimació de paràmetres de sistemes dinàmics utilitzant tècniques de filtratge 

    Brunet Crosa, Pere (Universitat Politècnica de Barcelona. Centre de Càlcul, 1979-03)
    Article
    Open Access
    El control de sistemes és tant més acurat com més precís és el model matemàtic del sistema controlat. En molts casos, això només es pot aconseguir amb un algorisme d'estimació en temps real dels seus paràmetres; i quan el ...
  • Feature-preserving downsampling for medical images 

    Díaz García, Jesús; Brunet Crosa, Pere; Navazo Álvaro, Isabel; Pérez, Frederic; Vázquez Alcocer, Pere Pau (European Association for Computer Graphics (Eurographics), 2015)
    Conference lecture
    Open Access
    In the medical imaging field, interactive direct volume rendering of large volume datasets is a challenging task. Multi-resolution techniques deal with this problem by downsampling the original dataset to produce coarser ...
  • From Degenerate Patches to Triangular and Trimmed Patches 

    Vigo Anglada, Marc; Pla García, Núria; Brunet Crosa, Pere (1996)
    Conference report
    Restricted access - publisher's policy