基于对象缓冲区的拾取法在地质体可视化中的应用

在三维地质体可视化中,需要操作者能够通过输入设备如鼠标来操纵屏幕上的物体,有时还需要获取物体的空间坐标或图形数值,这些都需要以拾取作为实现的基础。运用基于对象缓冲区的拾取方法。当用户要拾取一个物体时,在对象缓冲区中重画整个画面,把每个对象的标识符进行编码作为颜色值,然后,应用程序根据该像素的颜色值得到所要拾取对象的索引编码。通过得到的编码值能够快速、准确地搜索到所要拾取的对象,实现了在三维地质体中选择拾取有效地层的功能,避免了空间求交的复杂运算,速度快,并通过对象索引实现拾取被遮挡地层,在三维地质体可视化系统中获得了良好的应用效果。

Application of Object Buffer Pick-up Algorithm in 3D geology Volume Visualization

In 3D geology volume visualization system,need control the objects on screen with input device,sometimes need capture the space coordinates or value of the figure,all of these operation need to pick-up as the basis for realization.The Method of Pick Object Based on Object-Buffer was used in this system,which allowed users to select the effective targets quickly and exactly.While picking-up,redraw the whole image of object buffer,take the code of the object as the pixel’s color value through which the program can earn the index code of the object and find the target object.This system can void the complex operation of seeking intersection points in the space,and seek the final stratum,have a good application effect.