Search Results

Now showing 1 - 10 of 28
  • Item
    Editorial
    (The Eurographics Association and Blackwell Publishing Ltd, 2007) Duke, David; Scopigno, Roberto
  • Item
    Editorial
    (The Eurographics Association and Blackwell Publishing Ltd, 2006) Duke, David; Scopigno, Roberto
  • Item
    Exploiting the scanning sequence for automatic registration of large sets of range maps
    (The Eurographics Association and Blackwell Publishing, Inc, 2005) Pingi, Paolo; Fasano, Andrea; Cignoni, Paolo; Montani, Claudio; Scopigno, Roberto
  • Item
    Editorial
    (The Eurographics Association and Blackwell Publishing Ltd., 2006) Duke, David; Scopigno, Roberto
  • Item
    Detection of Geometric Temporal Changes in Point Clouds
    (Copyright © 2016 The Eurographics Association and John Wiley & Sons Ltd., 2016) Palma, Gianpaolo; Cignoni, Paolo; Boubekeur, Tamy; Scopigno, Roberto; Chen, Min and Zhang, Hao (Richard)
    Detecting geometric changes between two 3D captures of the same location performed at different moments is a critical operation for all systems requiring a precise segmentation between change and no‐change regions. Such application scenarios include 3D surface reconstruction, environment monitoring, natural events management and forensic science. Unfortunately, typical 3D scanning setups cannot provide any one‐to‐one mapping between measured samples in static regions: in particular, both extrinsic and intrinsic sensor parameters may vary over time while sensor noise and outliers additionally corrupt the data. In this paper, we adopt a multi‐scale approach to robustly tackle these issues. Starting from two point clouds, we first remove outliers using a probabilistic operator. Then, we detect the actual change using the implicit surface defined by the point clouds under a Growing Least Square reconstruction that, compared to the classical proximity measure, offers a more robust change/no‐change characterization near the temporal intersection of the scans and in the areas exhibiting different sampling density and direction. The resulting classification is enhanced with a spatial reasoning step to solve critical geometric configurations that are common in man‐made environments. We validate our approach on a synthetic test case and on a collection of real data sets acquired using commodity hardware. Finally, we show how 3D reconstruction benefits from the resulting precise change/no‐change segmentation.Detecting geometric changes between two 3D captures of the same location performed at different moments is a critical operation for all systems requiring a precise segmentation between change and no‐change regions. Unfortunately, typical 3D scanning setups cannot provide any oneto‐one mapping between measured samples in static regions: both extrinsic and intrinsic sensor parameters may vary over time while sensor noise and outliers additionally corrupt the data. In this paper, we adopt a multi‐scale approach to robustly tackle these issues, obtaining a robust segmentation near the temporal intersection of the scans and in the areas with different sampling density and direction.
  • Item
    Computer Graphics forum
    (Blackwell Publishing, Inc and Eurographics Association, 2003) Duke, David; Scopigno, Roberto
  • Item
    A Multiresolution Model for Soft Objects Supporting Interactive Cuts and Lacerations
    (Blackwell Publishers Ltd and the Eurographics Association, 2000) Ganovelli, Fabio; Cignoni, Paolo; Montani, Claudio; Scopigno, Roberto
    Performing a really interactive and physically-based simulation of complex soft objects is still an open problem in computer animation/simulation. Given the application domain of virtual surgery training, a complete model should be quite realistic, interactive and should enable the user to modify the topology of the objects. Recent papers propose the adoption of multiresolution techniques to optimize time performance by representing at high resolution only the object parts considered more important or critical. The speed up obtainable at simulation time are counterbalanced by the need of a preprocessing phase strongly dependent on the topology of the object, with the drawback that performing dynamic topology modification becomes a prohibitive issue. In this paper we present an approach that couples multiresolution and topological modifications, based on the adoption of a particle systems approach to the physical simulation. Our approach is based on a tetrahedral decomposition of the space, chosen both for its suitability to support a particle system and for the ready availability of many techniques recently proposed for the simplification and multiresolution management of 3D simplicial decompositions. The multiresolution simulation system is designed to ensure the required speedup and to support dynamic changes of the topology, e.g. due to cuts or lacerations of the represented tissue.
  • Item
    Editorial
    (The Eurographics Association and Blackwell Publishing Ltd., 2005) Duke, David; Scopigno, Roberto
  • Item
    A Statistical Method for SVBRDF Approximation from Video Sequences in General Lighting Conditions
    (The Eurographics Association and Blackwell Publishing Ltd., 2012) Palma, Gianpaolo; Callieri, Marco; Dellepiane, Matteo; Scopigno, Roberto; Fredo Durand and Diego Gutierrez
    We present a statistical method for the estimation of the Spatially Varying Bidirectional Reflectance Distribution Function (SVBRDF) of an object with complex geometry, starting from video sequences acquired with fixed but general lighting conditions. The aim of this work is to define a method that simplifies the acquisition phase of the object surface appearance and allows to reconstruct an approximated SVBRDF. The final output is suitable to be used with a 3D model of the object to obtain accurate and photo-realistic renderings. The method is composed by three steps: the approximation of the environment map of the acquisition scene, using the same object as a probe; the estimation of the diffuse color of the object; the estimation of the specular components of the main materials of the object, by using a Phong model. All the steps are based on statistical analysis of the color samples projected by the video sequences on the surface of the object. Although the method presents some limitations, the trade-off between the easiness of acquisition and the obtained results makes it useful for practical applications.
  • Item
    Computer Graphics forum
    (The Eurographics Association and Blackwell Publishing, Inc, 2004) Duke, David; Scopigno, Roberto