Decision algorithm for hot zone of irregular figure is the common one used in computer graphic processing.Applying the algorithms based on directed triangle area and on convex hull points set to process the hot zone of irregular figure has the disadvantages of huge computation complexity and inconvenient programming implementation,etc.So,according to the computer graphics and vector algebra,the recognition algorithm of cross product-angle-off set is put forward for hot zone of irregular figure.This method finds one by one the cross products and vector angles between the measuring point and the two adjacent points with same direction in irregular figure respectively,makes the signs of the vector angle and the cross product to be the same,and then calculates the sum of intersection angle.When the sum of intersection angle ≥ 6.0 or the point to be measured does not on the side boundary of the irregular figure,then the position of the measuring point is judged to be inside the irregular figure (that is,the hot zone).It is demonstrated by practical project application that the algorithm can correctly and rapidly recognise arbitrarily hot zone of irregular figure,and this meets the requirement of actual use.%不规则图形热区判定算法是计算机图形处理中的常用算法.基于有向三角形面积算法和凸包点集算法用于处理不规则图形热区,存在计算量大、不便编程实现等弊端.为此,根据计算机图形学及向量代数理论,提出不规则图形热区“叉积-夹角法”识别算法,该算法通过逐一分别求解被测点与不规则图形中同向相邻两点间的叉积及向量角,令向量角的符号与叉积符号同号,进而求取夹角和.当夹角和≥6.0或被测点位于不规则图形边线上,则判定被测点位于不规则图形内(即热区).经实际项目应用表明,算法能正确、快速识别任意不规则图形热区,满足实际使用要求.
展开▼
