Search Results

Now showing 1 - 2 of 2
  • Item
    INTERPOLATING CURVE NETWORKS WITH NEW BLENDING PATCHES
    (Eurographics Association, 1990) Saitoh, Tsuyoshi; Hosaka, Mamoru
    This paper describes methods of c o n s t r u c t i n g s u r f a c e patches which s a t i s f y independently given boundary conditions on a l l i t s four or t h r e e s i d e s . A patch c o n s i s t s of two p a r t s : one i s a patch s a t i s f y i n g a t l e a s t p o s i t i o n a l condition of the boundary curves, and the other gives n u l l position vectors and independent i t s f i r s t and second d e r i v a t i v e vectors on t h e i r boundaries. The l a t t e r i s used for compensating d e r i v a t i v e vectors t o s a t i s f y given boundary conditions. A network o f curves whose meshes are four or t h r e e s i d e s can be i n t e r p o l a t e d smoothly with patches of t h i s type.
  • Item
    On Formulation and Display for Visualizing Features and Evaluating Quality of Free-form Surfaces
    (Eurographics Association, 1990) Higashi, Masatake; Kushimoto, Takuya; Hosaka, Mamoru
    For evaluating quality of free-form surfaces and visualizing their features, various curves on a surface, which characterize its properties, are defined and their equations are deduced. Newly introduced curves include those of equi-gradient, silhouette, highlight and a locus of points of extremum gradient on contour curves, loci of points of extremum principal curvature on lines of curvature. The objectives of these curves and their uses are described. Other curves such as contour curves, its orthogonal ones, loci of points of zero curvatures, and lines of curvature as well as umbilics are also treated. Displays of these curves are shown.