基于Catmull-Rom算法的样条曲线在测绘CAD制图软件中的应用研究

Research on the Application of Spline Curve Based on Catmull-Rom Algorithm in CAD of Surveying and Mapping

传统测绘制图中对于不规则地物要素的绘制需要采集较多地形特征点,内外业工作量普遍较大,为解决该问题,研究了基于Catmull-Rom算法的样条曲线的地物绘制方法。首先对Catmull-Rom样条曲线的数学基础进行了分析,然后利用VB.NET基于AutoCAD开发了闭合面和非闭合面的样条曲线生成功能。实验结果表明,在不规则地物测绘与等高线绘制方面,Catmull-Rom样条曲线与其它种类的曲线相比平滑度较高且与实际情况非常吻合,在绘制非规则图形方面十分适用,能够显著提高测绘工作效率。

The drawing of irregular graphics in traditional surveying and mapping industry requires the collection of more terrain feature points.The workload is generally large.In order to solve this problem,we studied the method of spline curve drawing based on Catmull-Rom algorithm.Firstly,we analyzed the mathematical foundation of Catmull-Rom spline curve.Then we exploit the function of generating closed and non-closed surface splines based on AutoCAD by VB.NET.The experimental results show that the Catmull-Rom spline curve has a higher smoothness than other types of curves and it’s very consistent with the actual situation in the aspect of irregular terrain mapping and contour drawing.Catmull-Rom spline curve is very suitable for drawing irregular graphics.It can significantly improve the efficiency of surveying and mapping.