关键词: 形状参数, QTBé, zier, 连续性, 拼接

Abstract:

In order to  express and modify curves and surfaces, we design  quadratic trigonometric Bézier curves and surfaces with shape parameters. Firstly, we present a class of quadratic trigonometric Bézier basis functions with multiple shape parameters according to the properties of Bézier curves, and define the concept of quadratic trigonometric Bézier curves and surface with shape parameters. The properties are studied. The shape of the curves can be adjusted by altering the values of shape parameters while the control polygon is kept unchanged. With some particular shape parameters, special curves and surfaces are expressed, and rotating surface is constructed with different shapes. Quadratic trigonometric curves and surfaces with shape parameters can be a good representation of conic curves and surfaces. Since shape parameters are additional, so the interaction is more convenient.

Key words: shape parameters;quadratic trigonometric Bézier;continuity;joining