基于点的造型中如何计算采样点的法向量

A Normal Vector Computing Algorithm in the Point-Based Modeling

随着三维扫描技术的迅速发展,以及大量采样点数达百万数量级的高精度模型的产生,使得基于点的绘制技术逐渐成为热点。文章介绍了一种在基于点的造型中不必经过三角化,由采样点直接计算法向量的方法。该方法首先找到当前点周围的临近采样点;然后,根据最小二乘法由这些临近点近似计算当前点所在位置的切平面;最后,将切平面的法向量作为当前采样点的近似法向量。试验表明,该方法可以快速有效地计算采样点的法向量。

With the development of 3D-scanning technology and the appearance of large amount of high-precision modeling,the traditional geometric rending method can not meet the need of real time rending,So the technology of Point-Based Rending is becoming the new hotspot.In this paper,a normal vector computing algorithm is proved which needn＇t the triangles.Firstly,the nearly ones around the points should be found out.Secondly,it computes the tangent plane on the point＇s position approximatively using the least-squares algorithm with the around points.Lastly,it uses the normal vector of the tangent plane as the one of the point.The experience shows that the normal vectors of the sampling points can be figured out rapidly.