中文摘要：

在矩量法与物理光学方法混合时,需要准确快速地判断PO区域在点光源照射下的亮区和暗区,为此构造了一种高效率的遮挡消影算法.首先改进常用的Z-Buffer算法,将其用于对所有三角形面片进行分组,以降低计算量;然后在每组内采用一种严格的算法进行遮挡判断,以保持计算精度;最后采用区域分解方法来降低内存需求.具体的数值实验表明,该算法在维持内存量和计算时间基本相当的前提下,精度比Z-Buffer算法提高了18.6%.

英文摘要：

It is necessary to judge the lit region and the shadow region in the PO area when we use the MOM-PO hybrid method.This paper proposes a highly efficient method to complete this hidden face removal.First of all,it divides all the triangles in the geometric model into groups by the commonly-used Z-Buffer method,thus decreasing the time-expenditure.And then a strict method is adopted to find the lit triangles with high accuracy.Finally,we apply the domain decomposition method to decrease the memory requirement.A numerical experiment shows this new method can obtain a more accurate result than the Z-Buffer method by 18.6% at the expense of only a little more time and memory.