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。

-Experiments in model transformation based on the experiment through the realization of the following content, master OpenGL three-dimensional observation, perspective projection, orthogonal projection of the parameter settings, and can use the keyboard for mobile observation camera, in the perspective projection and orthogonal projection to switch between, the certification courses Three-dimensional observation of the content　further deepen their understanding of OpenGL matrix transformation of three-dimensional coordinates and the understanding and application.