The Terminator, Cameron's initial outing in the film franchise came out of a dream that he had. He believed in the idea with great fervor and even fired his agent who rejected the idea at the time. After the film went on to make a great deal of money for the low budget it had in 1984 a sequel began to be talked about, particularly by the film's star Arnold Schwarzenegger. Cameron and William Wisher would go on to write the sequel.
Cameron's influence on Terminator 2 is one that would become his staple for his career as the technology created in order to portray the T1000 on screen was developed for The Abyss as proof that it could be done for the next installment of the Schwarzenegger pic. Cameron, with a team of CGI experts would use the developed technology to allow the T1000 to shapeshift on screen, something that was not possible after the release of the first film in 1984. The director's use of this influence comes from the fact that what he sees in his mind is what he wants on the screen and he's willing to wait years or decades until the technology is advanced enough for him to have his imagination be captured in a realistic way on-screen.
Without this willingness to wait for the tech to be ready, Cameron would have simply sacrificed quality for attempting to hit it big with a sequel, which many filmmakers are pressured into in order to make a profit. But what we get from T2 is a completely fresh take on the new edition to the film's franchise and audiences agreed by paying nearly $600,000,000 globally to see Cameron's new film which include the technological advances never before seen on the silver screen. And that has become Cameron's brand: putting on-screen what only seems to be imaginable in the mind.
