Gershon Elber

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This paper presents a three dimensional interactive sculpting paradigm that employs a collection of scalar uniform trivariate Bspline functions. The sculpted object is evaluated as the zero set of the sum of the collection of the trivariate functions defined over a three dimensional working space, resulting in multi-resolution control capabilities. The(More)
This paper describes ‘Quick-sketch’, a 2D and 3D modelling tool for pen-based computers. Users of this system define a model by simple pen strokes, drawn directly on the screen of a pen-based PC. Exact shapes and geometric relationships are interpreted from the sketch. The system can also be used to sketch 3D solid objects and B-spline surfaces. These(More)
We present a new approach to building a solver for a set of geometric constraints represented by multivariate rational functions. The constraints are formulated using inequalities as well as equalities. When the solution set has dimension larger than zero, we approximate it by fitting a hypersurface to discrete solution points. We also consider a variety of(More)
This paper describes a hidden curve algorithm specifically designed for sculptured surfaces. A technique is described to extract the visible curves for a given scene without the need to approximate the surface by polygons. This algorithm produces higher quality results than polygon based algorithms, as most of the output set has an exact representation.(More)
Most o set approximation algorithms for freeform curves and surfaces may be classi ed into two main groups The rst approximates the curve using simple primitives such as piecewise arcs and lines and then calculates the exact o set operator to this approximation The second o sets the control polygon mesh and then attempts to estimate the error of the(More)
This paper discusses the principles of traditional mosaics and describes a technique for implementing a digital mosaicing system. The goal of this work is to transform digital images into traditional mosaic-like renderings. We achieve this effect by recovering free-form feature curves from the image and laying rows of tiles along these curves. Composition(More)
A technique is presented for line art rendering of scenes composed of freeform surfaces. The line art that is created for parametric surfaces is practically intrinsic and is globally invariant to changes in the surface parameterization. This method is equally applicable for line art rendering of implicit forms, creating a unified line art rendering method(More)
Offset curves have diverse engineering applications, which have consequently motivated extensive research concerning various offset techniques. Offset research in the early 1980s focused on approximation techniques to solve immediate application problems in practice. This trend continued until 1988, when Hoschek [1, 2] applied non-linear optimization(More)