说明：  ee~ 5-OpenGL视点坐标系与世界坐标系的相互对应关系，建立以视点系参考点为中心的球坐标，提出一种 新的三维场景旋转算法模型．该模型几何意义非常明确，在拖动过程中可随时调整灵敏度，在同等旋转条件下三维变化 导矢保持恒定，操作方便易行，为人机三维旋转操作提供了新的有效途径。
(ee ~ 5-OpenGL viewpoint coordinate and world coordinate system corresponding relationship between each other and establish a reference point as the center point of view series of spherical coordinates, a new algorithm for three-dimensional scene rotation model. Geometric meaning of the model is very clear, at any time in the process can drag to adjust the sensitivity, the same three-dimensional rotating conditions, changes in lead vector remains constant, convenient operation and easy, three-dimensional rotation operator for the machine provides a new effective way.)