VRML场景中的目标跟踪技术研究

Object-Tracing Technology in VRML Scenes

跟踪观察目标是虚拟场景漫游的关键技术之一。为克服固定或绑定视点的局限性,提出三种用VRML语言和脚本函数实现目标跟踪的方法,通过跟踪目标位置、实时计算相关参数来动态调整视点参数,使运动目标始终可见;阐述了实现原理,分析、对比了各种方法的控制复杂度及适用范围,并讨论了程序实现过程中需注意的问题。理论分析与实验表明:前两种方法实现简单,但适用范围有限;最后一种方法功能完善,可适用于各种环境,能很好地实现目标跟踪观察。

Object-tracing is one of the most important technologies to realize roaming in virtual environment.To overcome the limitation of fixed or bound viewpoints,three feasible methods are put forward to trace and observe targets,which were implemented by tracing target position,computing related parameters and modifying settings of viewpoints to keep the target in view.They were expounded in theory and realized by VRML language and script functions.In addition,pitfalls in programming were also discussed.Theoretical analysis and experimental verification show that the first two methods are easy to realize but with limited scope of usage,while the last one can perform object-tracing ideally with a little more cost of computing power.