And testing a vehicle ' s position related to the line of magnetic marks in the virtual trailing ground is simulated in favor of successive control models . ( 4 ) a simple roaming system is developed to realize cruising the 3d virtual scenes ( 4 )编写了一个简易的场景漫游系统，实现了三维场景的漫游显示、观察者视点的选择、键盘控制漫游参数等功能。
