Titlebook: Geometric Modelling; Dagstuhl 1996 Gerald Farin,Hanspeter Bieri,Tony Rose Conference proceedings 1998 Springer-Verlag Wien 1998 CAD/CAM.Com

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截断

Approximation of Curves by a Measure of Shape,ntroduced and its main properties are established. The measure is invariant under affine transformations and depends not only on the position vectors but also on the tangent vectors of the curves. An algorithm to compute the optimal Bézier approximant to a given curve is derived.

Aggressive

Shape Improvement of Surfaces,ace has to be faired. A fairing step is then applied, which locally modifies the control net by a constrained least-squares approximation. It consists of increasing locally the smoothness of the surface from .. to ... Some extensions of this method are also presented, which show how to build further methods by the same basic fairing principle.

大都市

A Philosophy for Smooth Contour Reconstruction, data. We show how to build an isocurve through any point and how to choose which isocurves are computed. The isocurves are used to build a tensor product surface for each component of the model isomorphic to a cylinder.

庇护

Fill-in Regions,terpolating curves with a desired shape. These regions are defined for special types of curves called coils, which are non-strict versions of curves of geometric order three in three dimensions. We establish that the fill-in regions are a set of tetrahedra and show how they must be restricted to form interpolating curves.

憎恶

胶状

A ,,-Subdivision Algorithm,we construct a subdivision algorithm with some negative weights producing ..-surfaces. These surfaces are piecewise bicubic and are flat at their extraordinary points. The underlying ideas can also be used to improve the smoothness order of subdivision algorithms for surfaces of higher degree or triangular nets.

Charlatan

Degree Reduction of B-Spline Curves,ves may easily be described in blossom form. We also use blossoms for the degree reduction problem, and set up least squares problems for finding the B-spline coefficients directly. We also give an application to curve fairing.

赤字

Conference proceedings 1998lization, and computational geometry.The following topics are treated:• surface design and fairing• subdivision schemes• variational design• NURBS• reverse engineering• physically-based modelling• medical imaging

Femine

0344-8029 ific visualization, and computational geometry.The following topics are treated:• surface design and fairing• subdivision schemes• variational design• NURBS• reverse engineering• physically-based modelling• medical imaging978-3-211-83207-3978-3-7091-6444-0Series ISSN 0344-8029