Reconstruction of quadratic curves in 3-D from two or more perspective views.
Reflection curves -- new computation and rendering techniques.
Reflections on spheres and cylinders of revolution.
RTIN-based strategies for local mesh refinement
Longest-edge bisection algorithms are often used for local mesh refinements within the finite element method in 2D. In this paper, we discuss and describe their conforming variant. A particular attention is devoted to the so-called Right-Triangulated Irregular Network (RTIN) based on isosceles right triangles and its tranformation to more general domains. We suggest to combine RTIN with a balanced quadrant tree (QuadTree) decomposition. This combination does not produce hanging nodes within the...
Shape-from-Shading, viscosity solutions and edges.
Smooth contour line construction with spline interpolation.
Contour maps are frequently used to represent three-dimensional surfaces from geographical applications or experimental results. In this paper, two new algorithms for the generation and display of such contours are presented. The first of them uses local spline interpolation to obtain contour maps from data points in a rectangular mesh, whereas the other interpolates a set of irregular points through recursive subdivision of triangles. In both algorithms, precision of the contours can be adjusted...
Surface-surface intersection: auxiliary spheres.
The Achilles' heel of ?
The best uniform quadratic approximation of circular arcs with high accuracy
In this article, the issue of the best uniform approximation of circular arcs with parametrically defined polynomial curves is considered. The best uniform approximation of degree 2 to a circular arc is given in explicit form. The approximation is constructed so that the error function is the Chebyshev polynomial of degree 4; the error function equioscillates five times; the approximation order is four. For θ = π/4 arcs (quarter of a circle), the uniform error is 5.5 × 10−3. The numerical examples...
The Coverage Model and Its Use in Image Processing
The CUDA implementation of the method of lines for the curvature dependent flows
We study the use of a GPU for the numerical approximation of the curvature dependent flows of graphs - the mean-curvature flow and the Willmore flow. Both problems are often applied in image processing where fast solvers are required. We approximate these problems using the complementary finite volume method combined with the method of lines. We obtain a system of ordinary differential equations which we solve by the Runge-Kutta-Merson solver. It is a robust solver with an automatic choice of the...
The Fourier Analysis of Bezier Curves
Tubular NURB surfaces with boundary control.
Tubular splines using a higher dimensional representation.
Uniform decompositions of polytopes
We design a method of decomposing convex polytopes into simpler polytopes. This decomposition yields a way of calculating exactly the volume of the polytope, or, more generally, multiple integrals over the polytope, which is equivalent to the way suggested in Schechter, based on Fourier-Motzkin elimination (Schrijver). Our method is applicable for finding uniform decompositions of certain natural families of polytopes. Moreover, this allows us to find algorithmically an analytic expression for the...
Visualisation of the electromagnetic vector fields
Modern computer algebra software can be used to visualize vector fields. One of the most used is the Maple program. This program is used to visualize two and three-dimensional vector fields. The possibilities of plotting direction vectors, lines of force, equipotential curves and the method of colouring the surface area for two-dimensional cases are shown step by step. For three-dimensional arrays, these methods are applied to various slices of three-dimensional space, such as a plane or a cylindrical...