轴对称物体图形的生成和阴影表示

The Generation and Shadow Display of Graphics for Objects of Axial Symmetrs

本文通过实例介绍轴对称物体图形的生成和阴影表示的图形处理技术。主要内容有:生成所需物体表面的轮廓图形;用三角形小块面(面素)去逼近物体表面;根据光照模型,视点位置和光源强度及方位,计算各面素的灰度值,在计算面素内部灰度的同时进行隐藏面的消除,从而可快速地实现图形的阴影表示。

This paper introduces the graphics processing technology of generation and shadow display of graphics for objects of axial symmetry by giving samples. The main contents indude: the generation of needful contour of object surface; the approximation of object surface with triangle facet ( surf ace elements ) ; the calculation of the grey level of the bounding surface elements in the light of the mode of illumination; the position of view point and the strength and orien tation of the light source(the eliminatition of hidden surface is completed while calculating the internal grey level of the bounding surface elements. This technology results in the realization of rapid display of graphics shadow.