It was nearing the end of Bafta's Ray Harryhausen 90th birthday tribute at the BFI Southbank last Saturday that special effects makeup maestro Rick Baker took to the stage to offer his praise. For the previous two hours or so, a stunning list of the movie industry's biggest, most innovative and respected names had, in person or via video messages, offered their undying love and gratitude to Harryhausen and his work, all offering incredibly specific tales of when they first encountered his unique contribution to cinema and how greatly it affected them. For Baker, the problem he faced was how could he say anything that had not been already said – even the "we are all children of the Hydra's teeth" line had been used. Twice. So, the six-time Oscar winner asked a question that, upon reflection, is rather terrifying, something no one else there would have dared to even speculate on: What if Ray Harryhausen had never been born? "I'd be asking you if you wanted fries with that ... Peter Jackson would be shearing sheep."

After that it was impossible not to consider how different cinema would be without such an inspiring figure. Just going by the list of acolytes who contributed to the evening alone, we'd have no Star Wars, no Terminator, no Toy Story, no Pan's Labyrinth, no Edward Scissorhands, no Jaws, no Shawshank Redemption, no Wallace and certainly no Gromit. Those are just the collateral damage, without Harryhausen there would be no Jason And The Argonauts, no 7th Voyage Of Sinbad and no 20 Million Miles To Earth. That's not a world I'd want to live in. It wouldn't be much fun.

Hosted by John Landis, who was funny and enthusiastic enough to have made this a memorable night even if no other guests had turned up, it was a joyful and emotional event. I'd even go so far as to say it was historic, legendary. The audience, full of people from Harryhausen's age downwards, all regressing to their nine-year-old selves, cooing and gasping at the clips spanning a unique body of work, as Landis interspersed the footage with an amazing collection of speakers, many of whom had flown across the world to be there: Baker, Randy Cook (Ghostbusters, The Thing), Bond/Hammer girl Caroline Munro, Sir Christopher Frayling, original ILM members Phil Tippet (who showed a special It Came From Beneath The Sea-inspired tribute short), Ken Ralston and Dennis Muren. Muren is the only FX artist, apart from Harryhausen, to have a star on the Hollywood walk of fame: he pulled out his wallet to show a picture of him meeting Harryhausen 48 years ago, a picture he has carried around ever since. Later that evening another ILM graduate told me what a big deal it was for the soft-spoken Muren to have told something so personal to such a large audience. It was a special night for everyone. Peter Jackson made the trip over with some of his early, Harryhausen-inspired home movies, including some sweetly hilarious footage of a 14-year-old him jumping around a New Zealand beach waving a sword – he'd heard for the skeleton fight in 7th Voyage Of Sinbad the live action had be filmed first, so he did the same, except he couldn't figure out how to add the skeleton to his footage, hence the lonely flailing.

There were many who could not be there, giving Landis an opportunity for some great jokey digs as he introduced filmed messages from the non-attendees: we got George Lucas (" too cheap to buy a ticket"), Steven Spielberg ("a young talent who could go places") and James Cameron ("his last couple of movies have been flops, it was the audiences fault, not his"). Best of all was Harryhausen's longtime friend Ray Bradbury, who told the tale of how they met, aged 18, for the first time outside the house of mutual pal Forrest J Ackerman (the man who coined the term "sci-fi" – these gentlemen pretty much invented everything). Invited back to check out Harryhausen's dinosaur models, Bradbury decided the two should be best friends and have spoken or met each other at least once a month for the last 72 years. I don't think anyone there failed to tear up over that. Beautiful.

It's not just in inspiring others that Harryhausen's name looms large, his methods still have impact on the technical side. I spoke to Gavin Rothery, the FX supervisor and designer on Moon who told me much of the current CGI compositing software is very strongly based on techniques Harryhausen used to insert his models into live action. And it's not just the film world that has benefitted: animator Stephen Czerkas has become a leading paleontologist, Darkplace actress Alice Lowe studied Greek classics at Cambridge following a love of the subject garnered from Jason And The Argonauts. Even One Million Years BC, a film often dismissed by non-scientific movie critics as it places dinosaurs and man together, has inspired many scientists as the dinosaurs are incredibly "best-guess" accurate in appearance and movement.

The evening ended with a wonderfully surreal drinks reception, with even more famous names such as Terry Gilliam, Edgar Wright ("Scott Pilgrim will be completed in two weeks, I promise"), Simon Pegg, Reece Shearsmith and Andy Serkis turning up. Chat was full of how people had gone the extra mile in preserving Harryhausen's legacy with a new book full of incredible photos I've never seen before (Ray Harryhausen: A Life In Pictures), an exhibition of his creatures at the London Film Museum and the guys behind the new Blu-Ray version of Jason And The Argonauts telling of how they have worked carefully at preserving the original look of the film by purposely not "correcting" the colours. Ray's daughter, Vanessa Harryhausen, told me about how she had the puppets of the alligator from The 3 Worlds Of Gulliver and the elephant from The Valley Of Gwangi as her childhood playthings. It occured to me that she could have seen her toys come to life by watching her dad's films, the closest to a real-life Toy Story anyone could get. But that's just one example of the magic Harryhausen has brought to everyone's lives. I'm going to book my ticket for his 100th birthday celebration now.