Now showing items 1-20 of 100

    • 3D model deformations with arbitrary control points 

      Cerveró Abelló, Maria Àngels; Vinacua Pla, Álvaro; Brunet Crosa, Pere (2016-06-01)
      Article
      Open Access
      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
      Open Access
      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 Language for constructive parametric solid modelling 

      Solano Albajés, Lluís; Brunet Crosa, Pere (1994-10)
      External research report
      Open Access
      The report discusses proposed solutions for constraint-based modelling, with special emphasis on constructive approaches. A new constructive scheme that overcomes a number of the present limitations is proposed. It is based ...
    • A multi-projector CAVE system with commodity hardware and gesture-based interaction 

      Andújar Gran, Carlos Antonio; Brunet Crosa, Pere; Vinacua Pla, Álvaro; Vico Moya, Miguel Ángel; Díaz García, Jesús (2017-01-12)
      External research report
      Open Access
      Spatially-immersive systems such as CAVEs provide users with surrounding worlds by projecting 3D models on multiple screens around the viewer. Compared to alternative immersive systems such as HMDs, CAVE systems are a ...
    • 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 scalable approach to T2-MRI colon segmentation 

      Orellana Bech, Bernat; Monclús Lahoya, Eva; Navazo Álvaro, Isabel; Brunet Crosa, Pere; Bendezú García, Álvaro; Azpiroz Vidaur, Fernando (2020-07-01)
      Article
      Restricted access - publisher's policy
      The study of the colonic volume is a procedure with strong relevance to gastroenterologists. Depending on the clinical protocols, the volume analysis has to be performed on MRI of the unprepared colon without contrast ...
    • A Solution to the problem of collision detection in large environments 

      Franquesa Niubó, Marta; Brunet Crosa, Pere (2000-06)
      External research report
      Open Access
      Collision detection between several objects in a closed space is an interesting research topic in all those areas where objects must not penetrate one another, such as Computer Graphics, Computer Vision, Virtual ...
    • 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 ...
    • Adaptive transfer functions: improved multiresolution visualization of medical models 

      Díaz García, Jesús; Brunet Crosa, Pere; Navazo Álvaro, Isabel; Pérez, Frederic; Vázquez Alcocer, Pere Pau (Springer, 2016-05-14)
      Article
      Open Access
      Medical datasets are continuously increasing in size. Although larger models may be available for certain research purposes, in the common clinical practice the models are usually of up to 512x512x2000 voxels. These ...
    • 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 ...
    • Alice 2.0: un visualizador interactivo de escenas 3D 

      Santisteve, Francisco Jose; Andújar Gran, Carlos Antonio; Brunet Crosa, Pere (1997-07)
      External research report
      Open Access
      This work describes the main features of a 3D visualizer called ALICE. This navigator has been developed over the Motif and OpenGL libraries by the Graphics Section of the L.S.I. departament in UPC. ALICE provides ...
    • 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, ...
    • Approximation of a variable density cloud of points by shrinking a discrete membrane 

      Esteve Cusiné, Jordi; Brunet Crosa, Pere; Vinacua Pla, Álvaro (2002-12)
      External research report
      Open Access
      This paper describes a method to obtain a closed surface that approximates a general 3D data point set with non-uniform density. Excluding the initial data points, any other previous information is not used (as, for ...
    • Automatic generation of multiresolution boundary representations 

      Andújar Gran, Carlos Antonio; Ayala Vallespí, M. Dolors; Brunet Crosa, Pere; Joan Arinyo, Robert; Solé Bosquet, Jaume (1996-01)
      External research report
      Open Access
      The paper focuses on automatic simplification algorithms for the generation of a multiresolution family of solid models from an initial boundary representation of a polyhedral solid. An algorithm for general polyhedra ...
    • Biharmonic fields and mesh completion 

      Argudo Medrano, Óscar; Brunet Crosa, Pere; Chica Calaf, Antonio; Vinacua Pla, Álvaro (2015-11)
      Article
      Open Access
      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 detection using multiresolution Kdtrees 

      Franquesa Niubó, Marta; Brunet Crosa, Pere (2001-07)
      External research report
      Open Access
      Collision detection between several objects in a closed space is of fundamental importance in all those areas where objects must not penetrate one another, such as computer grafics, robotics, motion planning, computer ...