It is phenomenally easy to forget when watching a modern film – particularly one of those explosion-laden, action-packed blockbusters – that a great deal of what we’re watching is not real, and never was. From digitally-painted landscapes to creatures formed and modeled inside a 3D-rendering program, computer-generated imagery has advanced in leaps and bounds since its inception in film in the late 1970s and early 1980s, and for many, it has become a staple of the movie-going experience: we expect to see the impossible when we go to see movies, and CGI has made virtually every impossible, possible.

I was discussing the impact of CGI with my son the other day, and we started talking about its history, the use of computers in film overall, and what some of the most impactful films over the past few decades have been in this regard. In doing so, it came to light that whilst some movies are famous for their outlandish and brazen CGI, others are recognized for implementing it in such a subtle way that we are completely fooled to the point of believing it must have actually happened.

As I think back over the past forty years of CGI, it occurred to me that there must be some movie, some film from each decade that stands out above all others for its inventive, innovative, and game-changing use of CGI, and I wanted to run down those top films – in my opinion – and they impact they’ve had on the film industry.

In order to measure up, of course, we can’t directly compare the CGI of Avengers: Endgame (2019) to that of, say, The Abyss (1989), because the technology is itself incomparable. To that end, I’m more interested in how the technology of the day was used in new and exciting ways, the believability of the effects it generated, and the long-term impact of the film’s use of technology on the film industry at large. I’ve picked one film from each decade since 1980, and will review what it achieved, how it achieved it, and what the film’s legacy is to this day.

1980s: Tron (1982)

The 1980s saw the burgeoning world of digital special effects explode into the mainstream, but it was also arguably the decade in which practical effects peaked, with sequences such as the face-melting scene in Indiana Jones and the Raiders of the Lost Ark and the werewolf transformations in An American Werewolf in London awing movie-goers around the world. In this context, it’s hard to see any movie from the 80s beat out practical effects with digital ones, but if there’s one movie that set the stage for what was possible with computers, it was 1982’s Tron.

The movie itself was never a big success at the box office, and the special effects used in it look primitive by today’s standards, but it was quite possibly the first mainstream film to extensively use computers to not only process but outright generate a great deal of its imagery. When Jeff Bridges first descends into the virtual world of his computer game, the neon lights and odd, geometric shapes whirling and dancing around the screen are entirely the product of specially-designed software, rotoscoped and superimposed against real-world footage.

Interestingly, the process of creating the digital ‘world’ in Tron was so complex, and required such precision with the film editing, that the cameras had to be bolted to the floor when filming those sequences so that there was as little change between shots as possible. This assisted the digital rotoscoping that helped to create the costume effects – essentially shot in black and white and then colorized – and helped to create the look and feel of the film. Despite the enormous difficulty in creating these shots, the film was actually disqualified from its year’s Oscar awards because using computers was considered cheating.

1990s: Forrest Gump (1994)

The 1990s was the decade that arguably advanced CGI to the point where it could be convincingly combined into real-life footage, seamlessly blending camera film and digital creations in ways that not only blew away the audiences, but left them wondering how it was done. From the outset, Terminator 2: Judgement Day (1991) set the decade up with its liquid metal person sequence that reportedly took over ten months to create, and movies like Independence Day (1996) ran with this creating entire air force fleets that never existed.

However, the film that stands out to me from the 90s as one of the most extensive, innovative, and convincing examples of CGI use in film has to be Forrest Gump (1994). This isn’t because it has entire CGI sequences (it doesn’t), nor because it moved away from practical effects (an enormous amount of the ‘clever’ shots in this film are untouched by CGI), but rather because when they did use CGI, they used it in such subtle, convincing ways that it becomes quite literally indistinguishable from real life.

Whether we’re looking at shots that have Tom Hanks interacting with long-dead presidents, or entire sequences where Gary Sinise’s legs are completely removed, the artful combination of digital and practical effects holds up to this day, even after twenty-five years. A large part of the film’s success came from innovative use of partial green screen and detailed rotoscoping, combined with the foresight when filming nearly every single shot that it might need digital tweaking afterwards. One of the shots that stands out is when Gary Sinise – missing legs and all – is lifted clear off a hospital bed and carried out by a nurse. This sequence was achieved by having the actor’s legs hidden through cutouts in the bed itself, and then digitally painting over those holes, frame by frame, in post-production.

For me, this film represents CGI subtlety at its very best, which is something I think we’ve sadly lost in more recent years with crazy camera angles, digital scenery, and sequences that are so clearly impossible that we lose our suspension of disbelief. With Forrest Gump, every shot and frame was so meticulously composed that you are simply immersed in the world created by Industrial Light & Magic, and the final shots put to film are nothing less than utterly convincing.

2000s: The Lord of the Rings: The Return of the King (2003)

George Lucas maybe have beaten Peter Jackson to the punch by a few years with the fully CGI character of Jar Jar Binks in Star Wars: The Phantom Menace (1999), but I don’t think there’s any argument that it was Weta’s work on Gollum in all three Lord of the Rings films that set the gold standard for what could be achieved with digital make-up and performance capture. And whilst we first see glimpses of the creature in The Fellowship of the Ring (2001) and entire sequences featuring Andy Serkis’ motion-capture in The Two Towers (2002), it was really The Return of the King (2003) that set a bar that would arguably not be beat until 2009’s Avatar.

The Lord of the Rings trilogy, of course, is famous for its liberal use of CGI to create everything from creatures to armies to entire landscapes, and for the most part it does it with absolute conviction; now, almost twenty years later, some scenes feel a little rough, but others remain as fresh as the day we first saw them in the cinema.

As with many films, there are a surprising number of practical effects throughout the Lord of the Rings movies, including model cities and landscapes built to such large scale that they coined the term ‘bigatures’ to describe them. However, it’s against the shots where practical and digital effects are seamlessly combined that truly showcase the talent of the digital effects team at Weta. Sure, giant spiders and armies of ghosts are visually striking, but the single shot that stands out to me to this day is early in The Return of the King, as we watch Andy Serkis play Smeagol’s descent into madness after coming into possession of the One Ring. To begin with we see Serkis unaided by CGI, and gradually watch a practical effects transformation into the creature, Gollum. However, there comes a point where the transformation has to be completed with CGI, and this is done in what may be one of the bravest CGI attempts of its time. Instead of simply cutting from a practical shot to a CGI shot, we watch as practical effect Serkis closes his eyes, only to seamlessly open them a moment later as a digital version of himself. The precise moment where the CGI takes over is completely indistinguishable, and represents perhaps one of the finest moments of subtle CGI integration in film to this day.

2010s: Dawn of the Planet of the Apes (2014)

The 2010s boast a plethora of CGI-laden films, from Marvel’s insanely ambitious cinematic universe to Disney’s ‘live-action’ remakes of classic animated films such as The Lion King (1994, 2019), and indeed will likely go down in history as the decade where CGI finally became indistinguishable from live action footage.

Standing on the shoulders of ground-breaking pioneers such as George Lucas, Steven Spielberg, Peter Jackson, and many others, the 2010s saw motion-capture take center stage as creatures and characters were brought to life with uncanny accuracy, from Mark Ruffalo’s Incredible Hulk to Josh Brolin’s Thanos, but over the past twenty years there is only one godfather of performance-capture, and that is Andy Serkis.

In an odd parallel to Tron’s disqualification from visual effects awards due to is heavy use of computers, Andy Serkis was repeatedly and similarly snubbed because it was felt that if we couldn’t actually see the actor, then we couldn’t judge them on their acting ability. And whilst Serkis certainly brought performance-capture to the mainstream with his work with Peter Jackson on The Lord of the Rings and Kong (2005), I maintain that his crowning achievement is as the chimpanzee Caesar in the Planet of the Apes trilogy in the mid 2010s.

To this end, of course, the CGI only improved in the years between these three films, but as a stand-out example of an absolutely seamless blend of CGI and real life footage, the second film in the trilogy – Dawn of the Planet of the Apes (2014) – opens with what can only be described as CGI perfection. Zoomed close in on Caesar’s face, Serkis manages to pull off an astonishing range of emotions – rage, fear, sadness and loneliness – in a sequence that only lasts a few seconds, and doesn’t contain a single pixel of his actual features. Instead, we read these emotions on the face of a digitally-built ape, and from the lighting to the individual movement of hairs and the flaking war paint around utterly believable eyes, there isn’t a frame that doesn’t look like the real thing.

The rest of the film, of course, is equally riveting and believable in its use of CGI, but this opening sequence – including dozens of apes hunting and killing deer and a freaking CGI bear – sets the stage, and the bar for the rest of the decade. Even five years later, Marvel’s work on Thanos only just manages to come close to what Weta (again) were able to achieve with Dawn of the Planet of the Apes.

Honorable Mention: Monsters, Inc. (2001)

If I were to include Pixar in the list of CGI breakthroughs, there would be no other movies included. Since 1995, Pixar have repeatedly showcased exactly what was possible with computers, creating not only breathtakingly beautiful animations through their custom-built software, but pushing the limits of what is technologically possible. As early as Toy Story 2 (1999), Pixar was experimenting with particle simulations, with one notable scene involving a toy penguin sneezing into a cloud of dust where every single particle was individually simulated.

However, one of the most groundbreaking innovations that came out of Pixar in the early 2000s was the ability to realistically animate and recreate hair: not just a few strands (as we see on Gollum in The Lord of the Rings), but in the case of Monsters, Inc. (2001) an entire body of hair. Every scene in which we see the monster Sully includes a complete simulation of hundreds of thousands of hairs, allowing for an almost hyper-realistic recreation of a creature that is literally covered in fur.

This arguably paved the way for later CGI creatures in other films, not the least of which has already been mentioned above: the apes in The Planet of the Apes trilogy. But more than that, it proved that with enough computing power, time and skill, quite literally anything can be digitally recreated in enough detail that the viewer will simply not be able to tell the difference. And as time goes on and the technology advances, so will the integration between CGI and real-world footage. We’ve already seen the beginning of a new era with Star Wars reviving dead actors through breathtakingly-convincing digital work, and I have no doubt that as we move into the 2020s, we will only see further proof that live-action scenery and actors may become a thing of the past – relegated to the history bin along with stop-motion and practical effects.

With that being said, the ability to create literally anything with a computer also means that the ability to visually stun audiences is fading away; when we saw James Cameron fly a helicopter under a bridge in Terminator 2: Judgement Day, it was all the more impressive because we knew that a real pilot (in that instance, it was literally flown by Cameron himself) actually performed the stunt. As impressive as the swarming spaceships of Infinity War and Endgame are, there’s still a part of me that knows, subconsciously, that what I’m watching simply isn’t real – and therefore simply isn’t as impressed.

So a word of caution: as far as we can push the envelope of digital film technology, there will (I hope) always remain a place for real-life action – if for no other reason than watching a real person jump out of a real moving vehicle will always be more stunning and impressive than any digital recreation of the same thing – regardless of how well it’s done.