3D-GIS中空间曲线绘制方法研究

应用二维曲线绘制中光滑效果比较好的张力样条函数方法研究了3D-GIS中空间曲线的绘制问题。在理论对比分析的基础上，选用某山区一段公路上的一组实测数据进行了模拟计算。结果表明，张力样条函数从理论上解决了取得空间两点间最短曲线的方法，能够很好地模拟3D-GIS中的空间曲线。而且节点间的距离不受限制，无论整条空间曲线上相邻数据点间距差别多大。其曲线外形都是一致的。如果数据点较多。可以分若干段处理，只要相邻端点条件一致，最终的整条曲线还是光滑的。

Method of drawing spatial curves in 3D-GIS

This paper studied the problem of how to draw spatial curve in 3D-GIS by tension spline function that is used extensively in drawing plane curves. Based on the comparison and analysis of the theory, a test about draning a section of spatial curve with the observation data of highway around a mountain was carried out. The results indicate that with tension spline function, the problem of how to obtain the shortest curve between two points is solved in theory and spatial curve can be well analogized out of the restriction of distance between two adjoining points. At the same time, the smoothness of spatial curve is very well. If the number of points is very large several sections can be dividedfrom the carve. Only if the condition of adjoining ponts is same, the whole curve is still smooth.