In our study, computer graphics are discussed and they are collected by the image sensor with an analog electrical signal. During acquisition of image, 3D space is relative to the camera system of different viewpoints with the same goals, it will cause the target respect to the change in orientation of imaging system and attitude, which will change the target in the imaging system. Images showed the same target image. Change the viewpoint to target in 3D space, which relative to the movement of the imaging system, such as change of the target rotation, translation and scale. We need to find or construct some sort of goal in order to make the motion or the target image features do not change. Such features and feature amounts are called invariance, and invariants. It is invariance only reflect the same characteristics or the same type of target, or that the nature with differences between different modes in the visual information. Because they are in 3D space with the target location, attitude and independent according to people who are easy to find the right target.