A few nights ago I caught a rerun of James Cameron’s Titanic (1997) on TV. Once again I marvelled at the achievement of the army of artists and technicians responsible for the ship’s near-mythic relaunch. Being a Southampton boy born and bred, the Titanic has been part of my consciousness for as long as I can remember, ever since my maternal grandfather showed me a larger than life-sized bronze memorial commemorating the event, constructed in one of the local parks.

This sculpture depicted members of the crew trapped in the engine-room, fighting hopelessly to keep the Atlantic at bay. Extremely realistic, it was made even more compelling by my grandfather’s incredible boast that he was the last man to leave the Titanic before her fateful maiden voyage began on April 10, 1912. He was a carpenter at the time, busy on some last-minute refinements to the ship on her way down Southampton Water. The work completed, he was dropped off at Cowes on the Isle of Wight, where he waved goodbye to the “unsinkable” liner.

But where would Cameron’s film be without special effects? There was a time when they were the exception rather than the rule, but those were the days when the end credits were half as long as they are today.

I’d been making feature films for 20 years before I felt the need to stretch the imagination of the audience beyond what the skilled model-maker or the make-up man could produce. A good early example of this effective combo was the silent film The Hunchback of Notre Dame (1923), in which Lon Chaney as Quasimodo swung from cathedral bells, depriving the citizens of Paris of a good night’s sleep if not the audience, who heard the bells only in their imagination. But those were the days before soundtracks were the norm. After that, the next big step forward came when it was found possible to stage realistic car chases without having to leave the studio. One simply projected a real car chase on to the studio screen, set up an immobile car in front of it and have the driver wiggle the steering wheel accordingly. And if the vehicle happened to be an open tourer, then a wind machine just out of shot could add a breezy thrill or two.

Compositing could put two different pictures together in one shot. When this process became available in colour, the sky was the limit. One of the most spectacular early examples was Michael Powell’s The Thief of Baghdad (1940), with its flying horses and magic carpets.

And by the time I got around to shooting Paddy Chayevsky's magic mushroom movie Altered States in 1980, almost anything was possible, although the process could be extremely painstaking. To achieve the spectacular special effect of Blair Brown turning into a sphinx during a sandstorm, one piece of film had to pass through the optical printer 27 times before being ready for developing. Unfortunately, it was thus impossible to tell if anything had gone wrong in all those 26 intricate processes on the way. Just one blemish and it was back to square one for all concerned, from special make-up to sand sculptors.

My latest big-screen effort included some modern, gimmicky CGI in the horror quartet Trapped Ashes (2006), in which a Hollywood starlet has breast enhancement, unaware that the tissue used is from a vampire. The unfortunate result is nipples that extend into piranha-type blood-sucking teeth when sexually aroused.

From the ridiculous to the sublime, freaky commercialism to painstaking research. OK, so we had the ridiculous spectacle of Leonardo DiCaprio and Kate Winslet acting like a dual figurehead, but on the other hand thanks to Titanic we have a pretty accurate picture of the greatest liner ever built. An attempt by a university to reconstruct the sinking would cost millions – if it got funding. So without being intentionally philanthropic, Hollywood is filling the gaps in our knowledge of the world.

Another good example is Spielberg’s Jurassic Park (1993). Not so long ago, when I wanted to get acquainted with prehistoric beasts I had to visit the Natural History Museum. Now I simply have to rent a copy of Jurassic Park to get a pretty accurate facsimile of the flesh actually covering those prehistoric bones, as well as how those monsters roamed the earth.

Once Jurassic Park was off and stomping through the landscape, the entire industry shifted wholesale from classic stop-motion animation to CGI digital effects. No more jelly to simulate the waves parting for Moses, as in The Ten Commandments (1956). Computers give more options, expressibility, speed and control. In The Day After Tomorrow (2004) a giant ocean liner can sail right down 5th Avenue. In The Perfect Storm (2000) floating in the valley of a 70ft wave communicates existential loneliness.

We got metal morphing into liquid in Cameron’s Terminator 2 (1991) and Trinity and Neo “freeze-stop” levitating in The Matrix (1999). We can cycle skyward with ET and Elliott or play Quidditch and fight a dragon with Harry Potter, and see empathic expressions and “believable” behaviour in trolls, gollums, orcs and apes.

We’ll even see magic spells, the goddess, chariots, Saxon freedom fighters and Roman hordes in my own Boudica Bites Back (2008), made with a handful of folk against green screen and an adept crew of digital animators.

In the future, we can expect the giant games industry to get involved in Hollywood films on an increasingly pervasive scale. We’ll be able to “be” the characters, controlling their moves, essentially co-scripting and starring with our neighbour in the next seat as we watch. Hollywood, here we come.

Explore Film

• Film Reviews

• DVD

• Oscars

• Bollywood

Editor's choice

• Here comes summer: our cultural must-sees
• Friends reunited: Sex and the City
• New country for old men