A right guard clipping region is the region outside of the viewport range in which the device can accept screen coordinates ; because the device can accept triangles that are partially or totally off - screen and within the guard band clipping region , the frequency of cpu - intensive clipping calculations can be reduced 右保护带剪辑区域是视区范围外的一个区域，在此区域设备可接受屏幕坐标；因为设备可以接受部分离屏或全部离屏但处于保护带剪辑区域的三角形，所以，可以减少大量占用cpu的剪辑计算的发生频率。
The left guard clipping region is the outside of the viewport range in which the device can accept screen coordinates ; because the device can accept triangles that are partially or totally off - screen and within the guard band clipping region , the frequency of cpu - intensive clipping calculations can be reduced 左保护带剪辑区域是视区范围外的一个区域，在此区域设备可接受屏幕坐标；因为设备可以接受部分离屏或全部离屏但处于保护带剪辑区域的三角形，所以，可以减少大量占用cpu的剪辑计算的发生频率。
During the realization of the prototype , it collects the video of real scenes firstly , identifies the markers in the video images to obtain the information of them , calibrates the camera parameter based on the markers ’ information , registers the virtual scenes and real world to obtain the relationship matrix of them , and finally realizes the blending of the virtual scenes and the real scenes 在系统实现过程中,系统首先采集现实场景视频,通过对视频图像中的marker进行识别,获取marker的相关参数,在获取这些信息的基础上定标摄像机的参数,对虚拟信息与真实世界进行配准,确定屏幕坐标与世界坐标的变换关系,最后将虚拟信息叠加到真实场景视频图像中,从而实现虚拟信息与现实场景的融合。
