When real images occlude virtual images,in other words real images are located in front of virtual images,the real images must occlude virtual images partly as in Fig2. It realizes the occlusion to visualize the virtual images which are hollowed out in the shape of the real image,as in Fig5. Hidden-surface removal is supported by OpenGL. So We only locate the polygon of the 3-D models of real images in front of the polygon of virtual images in virtual space in the form of OpenGL,provided that the polygon of the 3-D models of the real images are colored in the color of the background of the virtual space.
Fig５Real Images Occluding Virtual Images