Naturally, along with CGI, it wouldn’t mean much if real actors didn’t look as if they were in an unreal space. Green screens have seen the application since 1940, but there’s more to simply putting someone in front of a green piece of fabric and slapping them into a film to sell the feeling that the actor is very much present in that space. Though, before green screens were green, they were instead, blue. Blue screens were the cutting edge technology in the 70s, and Star Wars: The Empire Strikes Back is the best film to revolutionize the potential of blue screens. The spacecraft and the environment were all moving objects. Only the vast matte paintings of the giant asteroid served as the one solitary background element towards the end of the sequence. Asteroids rotate and collide with each other and TIE Fighters. Meanwhile, the Millennium Falcon slalomed through the obstacle course of moving rock. In 1980, the sequence was a jaw-dropping epic sequence that opened audiences' eyes to an exciting future in sci-fi cinema. On Empire, significantly more elements were shot separately in front of a blue screen and then composited together into a shot. The addition of scores of moving asteroids narrowly missing the Millennium Falcon pushed the blue screen to the limits.
Now with the widespread application of the green screen, they do more than just put an object or person into a certain space, they can very much take objects out of one. With the capabilities of chroma keying, you can have an actor wear an article of green clothing over a limb and chroma key that limb out, and for the film’s editors, you can make it appear as if that character had lost a limb entirely. The possibilities with green screening are limitless, and not only that, they inherently make film making easier.
Lastly, the evolution of motion capture. First used in 1915, motion capture has become an essential part of animated films, or films that apply CGI or visual effects, while still retaining a realistic element to them. Though, it wasn’t until 1988 that motion capture was used for animated characters. For things like Sega’s Virtua Fighter and Namco’s 1995 arcade game, Soul Edge, motion capture had been primarily used for video games, as there wasn’t an immediate push to use them in a full-length feature film because no one had ever really done it before.