Unity 3d tutorial to pinch and zoom camera

unity相机控制，可进行旋转缩放，查看，主要使用右键进行控制。(Unity camera control, can be rotating zoom, view, the main use of the right key to control.)

功能比较完善的相机切换脚本,可以通过右键移动相机朝向，滚轮缩放相机视距。(The camera switch scr ipt with perfect function can zoom in the camera's sight distance with the right key mobile camera and the roller.)