Browsing by Author "Serna, Sebastian Pena"

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    Effective Algorithm for Building and Solving Linear Systems
    (The Eurographics Association, 2021) Serna, Sebastian Pena; Silva, João; Stork, Andre; Marcos, Adérito Fernandes; Coelho, António and Cláudio, Ana Paula
    Several mesh-based techniques in computer graphics such as shape deformation, mesh editing, animation and simulation, build and solve linear systems. The most common method to build a linear system consists in traversing the topology (connectivity) of the mesh, producing in general a representation of the set of equations in form of a sparse matrix. Similarly, the solution of the system is achieved, by means of iterating over the set of equations in the default sequence of the vertices (unknowns). This paper presents a new algorithm, which optimizes the build of the linear system and its storage, and which allows the iteration over the set of equations in any arbitrary order. Additionally, our algorithm enables rapid modifications to the linear system, avoiding a complete rebuild.
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    Principal Curvature-Driven Segmentation of Mesh Models: A Preliminary Assessment
    (The Eurographics Association, 2021) Madeira, Joaquim; Silva, Samuel; Stork, André; Serna, Sebastian Pena; Santos, Luís Paulo and Fonseca, Manuel João and Dias, Miguel and Jorge, Joaquim A. and Santos, Vítor
    Three methods for triangle mesh segmentation, based on precomputed principal curvature values and using a region growing algorithm to label the vertices defining distinct surface regions, were developed, aiming at supporting the later manipulation of mesh models. Examples are presented, using different models, to illustrate their behavior. Results are promising but, in some cases, there is a clear need for a further post-processing step to refine the boundaries between adjoining regions and eliminate segmentation artifacts.