在视景仿真中用Hermite曲线控制物体运动

Controlling Movement of Objects by Hermite Splines in Virtual Scene

在视景仿真中利用关键帧方法控制物体沿曲线运动占有非常重要的地位,用于关键帧拟合的Cardinal曲线、Catmull-Rom曲线、Kochanek-Bartels曲线的引入切线和引出切线的生成方法由于没有直接利用起点和终点的参数而导致这些方法不适合在视景仿真中利用DOF节点控制物体运动的要求。为此提出了利用起点终点的直线距离生成Hermite曲线的方法,通过计算发现用该方法生成的曲线能有效地逼近原始曲线,如由圆形上的两点作为起点和终点,利用该方法生成的Hermite曲线可以有效的逼近圆形。最后将提出的生成Hermite曲线的方法应用到视景仿真系统中实现了物体的随时间变化沿Hermite曲线平滑运动。

It is important to control objects moving along some splines by the key frame method. Cardinal splines, Catmull-Rom splines, Kochanek-Bartels splines used in the key frame method to generate the incoming and outgoing tangents can not fulfill the requirement of controlling objects movement by DOF nodes in a virtual scene, because these splines can not be created by directly using the parameters of the starting and ending points. A new method to generate Hermite splines by the distance between the starting and ending points was proposed, and a circle curve could be approached by this method when selecting two points on the circle. Finally, the method was applied in a virtual scene system to control the objects moving smoothly along Hermite splines according to time.