在模型变换实验的基础上，通过实现下述实验内容，掌握OpenGL中三维观察、透视投影、正交投影的参数设置，并能使用键盘移动观察相机，在透视投影和正交投影间切换，验证课程中三维观察的内容；

进一步加深对OpenGL三维坐标和矩阵变换的理解和应用。

-In the model transformation experiments, based on the contents by implementing the following experiment, master OpenGL three-dimensional observation, perspective projection, orthogonal projection parameter settings, and can use the keyboard to move the observation camera, projection and orthogonal projection in perspective switch between authentication three-dimensional observation of the course content　further deepen the OpenGL three-dimensional coordinates and matrix transform the understanding and application.