中文摘要：

为实现三维地质模型中任意点的交互精确选取,借助OpenGL所提供的函数,提出了一种辅助线段滑块法。该方法首先计算鼠标所捕捉的屏幕点对应的三维空间直线,然后根据直线与地质模型的相交情况,得到一条由穿越地层组成的辅助选取线段。通过设置滑块在辅助线段上自由移动,即可实现三维地质模型中空间点的任意交互精确选取。应用实验表明,该选取方法精度高、适用性强,可以满足地质模型三维交互可视化与空间分析的需要。

英文摘要：

In order to realize interactive selection of arbitrary point in 3D geological model and based on the functions provided by OpenGL, an auxiliary segment sliding bar method is put forward. According to this method, a 3D spatial line corresponding with the 2D screen point caught by mouse should be calculated firstly. Then the line is used to intersect with 3D geological model, and an auxiliary selecting segment consisting of intersected strata is acquired. By setting a sliding bar freely moving along auxiliary segment, arbitrary interactive selection of 3D spatial point in 3D geological model is realized. Practical experiment shows this method is precise and flexible, and can meet the needs of 3D interactive visualization and spatial analysis of geological model.