This is a heuristic strategy . it can reduce the intersection tests need to be computed between bounding volumes by tracing the traverse process in previous time to gain traverse path in current time . the correctness and validity of collision detection can be guaranteed by maintaining the tracing list 这是一个启发式的策略，通过跟踪国防科学技术大学研究生院学位论文上一时间采样点对包围盒树的遍历过程，确定当前时间采样点的遍历路径，从而有效地减少了遍历过程中包围盒相交测试的次数，提高了算法效率，同时通过对跟踪表的维护，保证了碰撞检测的正确性和有效性。
