复杂地质曲面三维插值—逼近拟合构造方法

针对水利水电工程多源地质数据的特点,充分考虑了地质精度要求、曲面连续性和数据存储量等多方面的均衡,提出并实现了基于NURBS(non-uniform rational B-splines,非均匀有理样条曲线)技术的复杂地质曲面插值—逼近拟合构造方法。该方法对于工程关键区域集中且均匀分布的原始数据,采用NURBS蒙皮插值方法,使曲面严格通过这些数据点;对于周边区域分布离散的数据,采用NURBS逼近拟合方法,使曲面在给定精度下充分逼近原始数据;最后对整体曲面的地质结构合理性、几何性和精度进行检查分析和调整。实例表明,该方法所构造的地质曲面能满足地质工程师的实际需要,并能为进一步的三维地质建模提供基础。

3D interpolation approximation fitting construction method for complex geological surfaces

Based on multi source data, a fitting geological surface is required to achieve the balance among accuracy specification, continuity and storage. An approach of complex geological surface reconstruction which combines interpolation with approximation based on NURBS(non uniform rational B splines) technique is presented. The algorithm adopts the skinning method for densely and uniformly distributed data in the key region, and it ensures that all original data are on the built surface strictly. For the discrete data in the peripheral region, NURBS approximation fitting method is used to construct the corresponding surface, which approximates the data fully under the required accuracy. Finally, the integrated surface is analyzed and modified by checking the rationality of geological structure, geometry and accuracy. The instance shows that the approach can satisfy practical demands of engineering geologists and offer elements to further 3D geological modeling.