本程序是一个较大型的程序。它包含了多数的3D变换，3维形体的表示，消除隐藏面，真实感图形等知识，是一个理想的学习程序 -This program is a larger program. It contains most of the 3D transform, 3-dimensional shape representation, elimination of hidden surfaces, realistic graphics and other knowledge, is an idea