| Basing on the theories of interval analysis,geometry tolerance, interval Bezier curves,disk Bézier curves,this thesis has discussed two aspects of problems:(1)the properties of ball Bezier curves;(2)its application in blending of pipe surfaces;First , we mainly discusse ball Bezier curves.We introduced the disk arithmetic and the plane disk Bezier curves.A disk in the plane R~2 is denned to be the setThe following operations are defined for disks < C_i,r_i >,i = 0, ...,n:Notice that the addition satisfies the associative and commutative laws;furthermore,themultiplicati< of a ball by a scalar can be distributed over addition. Basing on disk arithmetic,we have the definition of disk Bezier curves as follows:where are the Bernstein polynomials of degree n.Ball Bezier curves possess some interesting properties which Bezier has: (l)End interpolation. (2)Affine invariant. (3)Convex hull. (4)De Casteljau algorithm (5)Subdivision(6)Degree elevation and reduction.We introduced the ball arithmetic and the ball Bezier curves.Let... |