本例的功能是显示茶壶图像的景深效果。再连续茶壶的图像中，其中一个处于焦点处，其他的茶壶随着其焦点处的距离而逐渐变得模糊-In this case the function is to show the image depth of field effects of teapots. Continuous re-pot image, where one is in focus at the other teapot with its focus at the distance gradually