As the world girds itself for the next-level immersive experience cooked up by “Avatar” impresario James Cameron, now would be a good time to remember “how we got here.”

In this digital effects world, Cameron may be the reigning king. But the people who put him there are less heralded visionaries, the people who really fought for this revolution.

One guy in particular might be the DaVinci of computer-animated special effects. Canadian-born animator and computer effects guru Steven “Spaz” Williams is the quirky, brawny, biker/blacksmith who got water to form face shapes in Cameron’s “The Abyss,” the fellow who let the mercury-in-motion T-1000 Terminator walk through fire and take human form, who let us believe that dinosaurs were again roaming the Earth.

Call him the “Jurassic Punk,” because no other nickname fits.

Director Scott Leberecht’s eye-opening and memory-jogging documentary is a Spaz Williams — an ironic geeky nickname, because “Look at me. I’m Popeye!” — appreciation and in many ways a rehabilitation project.

Williams was a key figure in changing how movies are made, a resident genius at the Oscar-winning Industrial Light and Magic effects house that George Lucas launched to bring movie making into the computer-assisted 21st century.

But clips of assorted Oscar-winning special effects speeches reveal that others, old school “film” (analog, hand-made, in-camera) effects supervisors, often his computer-naive bosses, got the credit for his innovations and “kept the little statues” for his stunning, hands-on/computer-assisted creations.

Still photos and home movies from his working years on films like “The Abyss,” “The Mask,” “Terminator 2,” “Jurassic Park” and the like show why that might have been. Williams is seen as a rebel in permanent arrested adolescence. He flips the bird at whoever was filming him scores of times in this brisk and entertaining trip through modern effects history.

“I’m not a diplomat,” Williams, now in his late ’50s admits. “Never have been.” Not that we haven’t figured that out. “I’m not political. No good at it.”

Old school stop-motion modeler Phil Tippett, a guy working in the Ray Harryhausen puppet effects style that dates back to the birth of cinema and the original “King Kong,” appears here. He’s someone whose craft Williams helped render obsolete during the making of “Jurassic Park.” Tippett was among those who shared Oscars for “Jurassic Park,” even though Steven Spielberg — upon seeing Williams’ spare-time renderings of how he could animate dinosaurs into more natural motion via computers — made “Jurassic” an all-digital effects shoot, never using Tippett’s planned models.

Williams’ ILM nemesis, the oft-honored Dennis Muren, who won many Oscars despite not knowing much at all about computer effects, is only seen in old interviews. It’s hard not to see Muren, who seemed to go out of his way not to “thank” Williams in his “boss man gets the statue” speeches, as the villain of “Jurassic Punk.”

It’s also easy to see Williams himself as a villain, his own worst enem. He’s a self-defeating maverick who drank to excess, chasing away the mother of his child, wrecking a later marriage, threw wild parties in the ILM effects “pit” (room where animators work together), crashed into Lucas’s office at Skywalker Ranch during a celebratory dinner, and generally flipped-off authority at every turn. Obviously being brilliant and a good “team player” and colleague to his peers, even if never quite fit in with them, wasn’t enough.

“Art is about always questioning established systems,” he lectures digital art students. “Authority” makes him bristle, even today, because “When you think differently, you’re seen as a ‘heretic.'”

The film has Williams lamenting the way this reliance on big effects houses has “destroyed filmmaking,” with movies like “Scooby-doo” and “Casper” and others (Marvel’s many CGI-heavy outings are ignored, as are the “Transformers” movies) abusing the new “magic,” and running up costs so much that film is no longer an artist, actor’s, creator’s or “director’s” medium, but a corporate one.

True enough. But “Jurassic Punk” is great when it recaptures the days when Spaz Williams, his fellow computer effects “punk” (and “Spawn” director and collaborator) Mark Dippe’ and others were showing up to work at ILM and asking “How’re we gonna do THAT?” When nobody else had the answer, they came up with one, and then others.

Williams notes how many months it took to film “75 frames” of this piece of “Jurassic Park,” and we see the gridwork drawn on actor Robert Patrick so that they could do what had never been done before in “Terminator 2,” “building a human in data” via motion capture cameras that would pick up on every muscle movement that needed to be replicated to make molten metal walk like a human being in a police uniform before that uniform ever forms on screen.

Spielberg, speaking in a 2013 interview about the history of the “Jurassic” shoot, remembers saying of Williams’ test-animation of a T-rex skeleton walking and nibbling through “Jurassic Park,” “That’s the future…That’s the way it’s gonna be from now on.”

He was right. And now we have a documentary to tell who we have to thank for all the wonders that the movies have shown us since.

Rating: unrated, smoking, profanity

Cast: Steven “Spaz” Williams, Mark Dippe’, Phil Tippet, Adrienne Biggs, Hannah Williams, Jody Duncan, archival interviews with James Cameron, Dennis Muren and Steven Spielberg

Credits: Directed by Scott Leberecht. A Gravitas Ventures release.

Running time: 1:21