复杂三维地层建模及快速射线追踪的研究与实现

利用射线法进行三维正演模拟,需要建立三维地层模型,并进行三维射线追踪.然而三维地层建模,特别是复杂模型的构造通常比较困难,为此提出了一种利用二维地质剖面构建三维地层模型的算法,该方法以用户编辑的二维地质剖面作为原始资料,自动构造初始模型,经细化处理后输出光滑、细腻、合理的三角网格模型,有效地解决了复杂地层建模的问题.离散的三角网格可以描述复杂的地质构造,但是由于包含大量三角形,使得射线追踪效率比较低.因此介绍了利用空间包围盒在三角网模型上进行快速射线追踪的方法,利用该方法可以在复杂模型上快速完成上万条射线的射线追踪,追踪速度快而且精度高,具有很强的实用价值.

Research and realization of complex three dimensional stratum modeling and fast ray tracing

Three dimensional forward modeling using ray method needs 3D stratum modeling and 3D ray tracing. However, 3D stratum modeling, especially for the complex model structure, is very difficuh. This article proposed an algorism to built 3D stratum model using 2D geological cross-section. This method takes 2D geologic cross-section edited by users as the basic data, with which initial model will automatically form; after careful treatment, a smooth, fine and rational triangular network model will yield, which can effectively solve the complex stratum modeling problem. The discrete triangle grid may describe the complex geologic structure, but its ray tracing efficiency is quite low due to its including of ninny triangles. This paper introduced the method to realize the ray fast tracing with space surrounding box on triangular net model, therefore, it is possible to complete the ten thousands strip rays tracing on complex model with quick speed, high accuracy and strong practical value.