23-Issue 4Regular Issuehttps://diglib.eg.org:443/handle/10.2312/1172024-03-28T20:33:21Z2024-03-28T20:33:21ZSmooth Surface Reconstruction Using Tensor Fields as Structuring ElementsVieira, M. B.Martins, P. P.Araujo, A. A.Cord, M.Philipp-Foliguet, S.https://diglib.eg.org:443/handle/10.2312/101012017-03-16T13:53:38Z2004-01-01T00:00:00ZSmooth Surface Reconstruction Using Tensor Fields as Structuring Elements
Vieira, M. B.; Martins, P. P.; Araujo, A. A.; Cord, M.; Philipp-Foliguet, S.
We propose a new strategy to estimate surface normal information from highly noisy sparse data. Our approach is based on a tensor field morphologically adapted to infer normals. It acts as a three-dimensional structuring element of smooth surfaces. Robust orientation inference for all input elements is performed by morphological operations using the tensor field. A general normal estimator is defined by combining the inferred normals, their confidences and the tensor field. This estimator can be used to directly reconstruct the surface or give input normals to other reconstruction methods. We present qualitative and quantitative results to show the behavior of the original methods and ours. A comparative discussion of these results shows the efficiency of our propositions.
2004-01-01T00:00:00ZStellar Mesh Simplification Using Probabilistic OptimizationAntonio W. VieiraThomas LewinerLuiz VelhoHelio LopesGeovan Tavareshttps://diglib.eg.org:443/handle/10.2312/101022017-03-16T14:36:49Z2004-01-01T00:00:00ZStellar Mesh Simplification Using Probabilistic Optimization
Antonio W. Vieira; Thomas Lewiner; Luiz Velho; Helio Lopes; Geovan Tavares
2004-01-01T00:00:00ZPhysical Validation of Global Illumination Methods: Measurement and Error AnalysisRoland SchregleJan Wienoldhttps://diglib.eg.org:443/handle/10.2312/100982017-03-16T14:25:40Z2004-01-01T00:00:00ZPhysical Validation of Global Illumination Methods: Measurement and Error Analysis
Roland Schregle; Jan Wienold
In this paper, we present a physical validation of global illumination algorithms based on measurements from a simple experimental setup. The validation methodology emphasizes tractability and error minimization. To this end, we discuss issues such as the acquisition and accurate simulation of material bidirectional reflection distribution functions (BRDFs) and the light source distribution, as well as error analysis. In addition, we present a nearest-neighbor resampling technique for BRDFs and a simple method for extracting the light source distribution from digitized high dynamic range (HDR) images. Finally, we compare the measurements to a forward and backward raytracing solution (photon map and RADIANCE, respectively) in a set of case studies.
2004-01-01T00:00:00ZPara-Graph: Graph-Based Parameterization of Triangle Meshes with Arbitrary GenusGiuseppe PataneMichela SpagnuoloBianca Falcidienohttps://diglib.eg.org:443/handle/10.2312/100992017-03-16T15:01:33Z2004-01-01T00:00:00ZPara-Graph: Graph-Based Parameterization of Triangle Meshes with Arbitrary Genus
Giuseppe Patane; Michela Spagnuolo; Bianca Falcidieno
This paper describes a novel approach to the parameterization of triangle meshes representing 2-manifolds with an arbitrary genus. A topology-based decomposition of the shape is computed and used to segment the shape into primitives, which define a chart decomposition of the mesh. Then, each chart is parameterized using an extension of the barycentric coordinates method. The charts are all 0-genus and can be of three types only, depending on the number of boundary components. The chart decomposition and the parameterization are used to define a shape graph where each node represents one primitive and the arcs code the adjacency relationships between the primitives. Conical and cylindrical primitives are coded together with their skeletal lines that are computed from and aligned with their parameterization. The application of the parameterization approach to remeshing guarantees that extraordinary vertices are localized only where two patches share a boundary and they are not scattered on the whole surface.
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