这是一个OpenGL写的后视镜的文章，文章中采用了离屏渲染的技术将照相机后面的场景采集下来，之后将其显示在后视镜模型上。-This is a mirror of the articles written by OpenGL, the article used in the off-screen rendering technology to capture the scene behind the camera down, and then display it in the mirror model.