（1） The traditional makeup technique of changing faces with physical objects. Early film face changing techniques were an extension of physical makeup techniques. Physical face swapping is a process in which makeup artists reconstruct various facial features in three-dimensional structures using materials such as plaster, silicone, hair, and paint, based on the actor's original face, in order to reshape a new image. The advantages of physical makeup are fast implementation, low material cost, and high degree of facial three-dimensional transformation. Physical face swapping is a traditional makeup technique that has been used to this day and has become one of the standard techniques in the film industry. On the one hand, the production cost of CG special effects is relatively low, and on the other hand, actors wearing makeup will perform more deeply into their characters, enhancing the authenticity of the movie on the screen. However, the physical face changing technique highly relies on the precise control of facial 3D features by special effects makeup artists and their proficient comprehensive use of makeup materials. Secondly, the burden on actors is heavy, and their ability to express emotions is limited. That's also why the characters in physical face swapping techniques are often set as non-human characters.
