一种面向移动计算终端的几何压缩方法

A Geometry Compression Method for Mobile Computing Terminal

鉴于移动计算终端具有显示屏幕小、对模型精度要求较低和处理能力相对较弱、处理高细节度的模型十分吃力,以及受带宽所限,需要对模型进行渐进传输等特点。而已有的几何压缩和简化方法又对移动计算终端的这些特点针对性不够,为此,围绕在移动计算终端上进行3维图形的显示,根据移动计算终端的特点,提出了一个实现过程简单、简化效率较高的几何压缩方法,同时提出了一个基于顶点相邻三角形单位法向量变化的边折叠几何压缩算法,并通过计算顶点相邻三角形单位法向量差值来识别出模型的特征点,提出了一个特征保留的策略。实践表明,完整的基于单位法向量变化和特征保留的边折叠几何压缩算法可以在保持模型外观的同时,有效地降低模型的规模。最后给出了该压缩方法在移动计算终端上的应用情况。通过用该压缩算法对模型进行预处理,实现了在移动计算终端上进行3维图形显示的这一目的。随着移动计算技术的发展,移动3维图形的应用将会越来越多,因此该压缩方法在移动3维图形计算方面具有较好的应用前景。

The characteristics of the mobile computing terminal are the following： the display is small and it need not much information in detail, the performance is low and it is difficult to process the models with high details, the bandwidth of wireless network is narrow and it needs a progressive transmission. Because other geometry compression or simplification methods did not aim at these characteristics, this paper focuses on displaying 3D graphics on mobile computing terminals and is designed for terminals with these characteristics, proposed a simple and effective compression method. This paper puts forward an edge collapse arithmetic based on the change of triangle normal, which surrounds the vertex. We also proposed a characteristic preservation method based on computing the difference of triangle normal. The whole method reduces the size of 3D model while retaining the appearance. After applying this arithmetic to 3D models, the goal of displaying 3D graphics on mobile computing terminals is accomplished. With the development of mobile technology, the application of mobile 3 D graphics will be increased, and this method will have a wider prospect in mobile 3 D graphics field.