快速计算虚拟物体之间精确接触位置的算法

在触觉、力觉交互的虚拟现实系统中,快速计算虚拟物体之间精确接触位置是触觉、力觉交互碰撞检测系统的前提.在这样的系统中虚拟物体大多是多面体模型且是三角形模型,采用层次包围盒法判断物体是否相交,如果相交,采用本文提出的二级检测算法快速计算出物体的接触位置.该算法首先判断那些相交三角形是异面还是同面,如果是异面,求出一个三角形T₂与另外一个三角形T₁所在平面的交线,然后再判断该交线与T₁之间的位置关系,进而求出有效的相交线段;如果是同面,需要判断两个三角形之间相互位置关系,然后有针对性地求出相关线段之间的交点,从而求出三角形的相交区域.最后用实例验证了该算法的有效性和鲁棒性.

Algorithm of fast calculate exact contacted position among virtual objects

In the virtual reality interactive system of the force-feedback or touch-feedback,fast calculating exact contacted position among virtual objects is precondition of these collision detection systems. Because the model of these systems is most polygon model, the collision detection algorithm of hierarchy bounding box was taken to determine whether two objects contact or intersect, if intersected, the two-step algorithm was taken to detect the contact position. At first, determine whether the intersected triangles are in the same plane or in the other plane; if in the other plane, calculate the intersected line of one triangle T_2 and the plane of another triangle T_1, then determine which line of the triangle T_1 that will intersect the intersected line, and calculate the intersected point, now the final intersected line is received at this case; if in the same plane, determine the relationship of the two triangles, and calculate the intersected point of the lines which are intersected, and do not calculate the intersected point of the lines which are not intersected( thus it conduce to the fastness of the algorithm), the final intersected region or lines is received at this case. Three examples show the effectiveness and robustness of the algorithm.