几何不变性 meaning in English

geometrical invariability

According to properties of h - bezier basis , h - bezier curves are endowed with wonderful geometric properties including interpolating at endpoints , convex hull , affine invariance and optimal shape preserving . furthermore , a shape factor of the h - bezier curve is introduced to control the shape of the designing curves
基于h - b zier基函数的几何性质， h - b zier曲线具有适合cad中曲线建模和形状设计的保形性，端点插值性，凸包性，几何不变性和形状控制等很好的几何性质
Secondly , we introduce the recurrence definition of the non - uniform algebraic - hyperbolic b - spline basis using divided differences and the de boor - fix recurrence definition on polynomial functions , and based on the new forms , algebraic - hyperbolic b - spline curves are obtained . they share most of the properties as those of the b - spline curves in the polynomial space . we focus on deducing the calculating and knot inserting formulae for this new kind of curves and then prove that they have the variation diminishing properties
二、利用广义差商,基于多项式b样条的deboor - fix递推定义,给出了任意阶非均匀代数双曲b样条的递推定义,由此构造曲线,证明它的几何不变性、仿射不变性、凸包性、 v . d .性等,重点给出了非均匀代数双曲b样条曲线的递归求值和节点插入算法,算法简单且稳定,便于在计算机上实现