一种适用于球面局部区域的纹理映射算法

两步纹理映射和环境映射一般都采用球面作为中介曲面，由于球面映射算法是这两种纹理映射技术的重要组成部分，且球面映射算法还可应用于自由曲面的识别和视景生成等方面，因此，对球面映射算法进行研究具有重要的意义，为了进一步减少球面映射算法产生的纹理形变，从纹理不变形准则出发，分析了传统球面纹理映射算法及其不足之处，并在此基础上提出了一种适用于局部球面的纹理映射新算法，由于该算法考虑了面积等比约束关系，因此可显著提高纹理映射质量，实验结果表明，该算法十分有效，具有一定优势。

An Algorithm of Texture Mapping Applicable to Partial Area on Spheres

In the methods of two part texture mapping and environment mapping, a sphere is usually used as the intermediary surface, where a kind of sphere mapping algorithm is contained as their important component. Furthermore, the algorithm of sphere mapping may also be applied in recognition of surfaces and generation of landscapes, etc. In order to decrease the texture distortion caused by the algorithm of sphere mapping, the paper discusses the traditional algorithms of sphere mapping and its shortcomings at first according to the non|distortion criterions of sphere texture mapping. And then, a new algorithm of texture mapping is put forward, which is applicable to partial area of a sphere. Because the ratio of areas between a texture region on the texture plane and the corresponding mapping region on the partial sphere is used as a constraint, the quality of texture mapping is obviously improved. Finally, some of the experimental results are presented, which show that the new algorithm is quite effective and has certain advantage compared to the traditional algorithms of sphere mapping.