The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper introduces paper-strip sculptures, a physical mesh data-structure used to represent 2-manifold mesh surfaces for understanding topological and geometrical aspects of shape modeling with visual and tactual examples. With paper strips it is possible to construct simple paper sculptures that can convincingly illustrate a variety of ideas in shape modeling - such as 2-manifold mesh surfaces,...
Reconstructing tubular structures with high-order branching is a difficult task to perform automatically. Medical applications in particular demand accurate models of such objects that fulfill specific topological and geometric criteria. Indeed, the reconstructed object should be a 2-manifold surface with compact, adaptive geometry. We present a generic algorithm for automatically reconstructing n-furcated...
This paper presents a benchmarking system for the evaluation of robust mesh watermarking methods. The proposed benchmark has three different components: a ''standard'' mesh model collection, a software tool and two application-oriented evaluation protocols. The software tool integrates both geometric and perceptual measurements of the distortion induced by watermark embedding, and also the implementation...
Ridges are extremal curves of principal curvatures on a surface that indicate salient intrinsic features of its shape. This paper presents a novel approach for extracting ridges of improved quality from isosurfaces of volumetric scalar-valued grids by converting them to implicit trivariate B-spline representations. A robust tracing approach demonstrated to extract ridges accurately from parametric...
This paper develops a new trivariate hierarchical spline scheme for volumetric data representation. Unlike conventional spline formulations and techniques, our new framework is built upon a novel parametric domain called Generalized PolyCube (GPC), comprising a set of regular cubes being glued together. Compared with the conventional PolyCube (PC) that could serve as a "one-piece'' 3-manifold...
Advances in modeling of discrete models have allowed the development of approaches for direct mesh modeling and modification. These tools mainly focus on modeling the visual appearance of the shape which is a key criterion for animation or surgical simulation. Most of the time, the resulting mesh quality as well as the semantics preservation capabilities are not considered as key features. These are...
Sectional views are widely used in engineering practice due to their clear and concise expression. However, it is difficult for computers to understand because of the large numbers of omitted entities and their diversified representations. This paper aims at reconstructing 3D models from 2D sectional views by improving the traditional volume based method. First, we present a two-stage loop searching...
Panoramic projections are often defined by the geometric surfaces used to derive the projections' equations (e.g., spherical and cylindrical panoramas). The parameterization of these surfaces greatly affects the resulting projection equations and image properties. Problematically, unusual parameterization can reproduce panoramas associated with other shapes. In this paper, we ensure an explicit link...
This paper presents a novel 3D shape retrieval method, which uses Bag-of-Features and an efficient multi-view shape matching scheme. In our approach, a properly normalized object is first described by a set of depth-buffer views captured on the surrounding vertices of a given unit geodesic sphere. We then represent each view as a word histogram generated by the vector quantization of the view's salient...
We present an implicit approach for pair-wise non-rigid registration of moving and deforming objects. Shapes of interest are implicitly embedded in the 3D implicit vector space. In this implicit embedding space, registration is performed using a global-to-local framework. Firstly, a non-linear optimization functional defined on the vector distance function is used to find the global alignment between...
The level set method can implement a wide variety of shape modeling operations (e.g. offsetting, skeletonization, morphing, blending, smoothing, sharpening, embossing, denoising, sculpting, growing, texturing and fitting) simply by specifying a corresponding speed function that controls the growth of an evolving voxel isosurface. The problem is that the basic level set method is implemented on a fixed...
We present a new algorithm, based on the concept of contributing vertices, for the exact and efficient computation of the Minkowski difference of convex polyhedra. First, we extend the concept of contributing vertices for the Minkowski difference case. Then, we generate a Minkowski difference facets superset by exploiting the information provided by the computed contributing vertices. Finally, we...
Skeletal implicit modelling systems have been used to design models of both organic and man-made structures, however existing systems lack convenient and accurate methods for users to define fillets when building prototype engineering models. In this work we extend the methodology and skeletal primitives found in the BlobTree and introduce an improved method for modelling fillets. This is done by...
We exhibit the essentially unique projective linear (rational linear) reparameterization for constructing Cs surfaces of genus g>0. Conversely, for quadrilaterals and isolated vertices of valence 8, we show constructively for s=1,2 that this map yields a projective linear spline space for surfaces of genus greater or equal to 1. This establishes the reparametrization to be the simplest possible...
In digital geometry processing and shape modeling, the Laplace-Beltrami and the heat diffusion operator, together with the corresponding Laplacian eigenmaps, harmonic and geometry-aware functions, have been used in several applications, which range from surface parameterization, deformation, and compression to segmentation, clustering, and comparison. Using the linear FEM approximation of the Laplace-Beltrami...
N-sided hole filling plays an important role in vertex blending. Piegl and Tiller presented an algorithm to interpolate the given boundary and cross-boundary derivatives in B-spline form. To deal with the incompatible cases that their algorithm cannot handle, we propose an extension method to manipulate the transition between sharp and rounded features. The algorithm first patches n crescent-shaped...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.