Abstract :
This paper describes two algorithms which find the visible portions of surfaces in a picture of a cluster of three-dimensional quadric patches. A quadric patch is a portion of quadric surface defined by a quadratic equation and by zero, one, or several quadratic inequalities. The picture is cut by parallel planes called scan planes. The visibility problem is solved in one scan plane at a time by making a "good guess" as to what is visible according to the visible portions found in the previous scan plane.
Keywords :
Computer-aided design, curved surfaces, curvilinear surface representation, data structures, halftone pictures, hidden lines, visible surfaces.; Cities and towns; Clustering algorithms; Computational complexity; Computer science; Computerized monitoring; Data structures; Equations; Polynomials; Rough surfaces; Surface roughness; Computer-aided design, curved surfaces, curvilinear surface representation, data structures, halftone pictures, hidden lines, visible surfaces.;
