One foggy morning in 2007, screenwriter Travis Beacham was walking along the beach in Santa Monica and he looked out at the famed amusement park pier jutting out into the water. His imagination ever running rampant, he pictured behind those mist-covered, empty rides a towering machine, a robot — a mech, actually — waiting to do battle with some vicious monstrosity. The germ of “Pacific Rim” was born.

A treatment, a screenplay, an epic production and six years later, that vision is about to take hold outside of the writer’s imagination and on screens nationwide. Directed by Guillermo del Toro, it’s an original concept at a hefty price tag without the benefit of star power or a built-in fanbase. Those unique elements have cast a dark industry shadow on the film’s opening weekend prospects, but for Beacham, it’s all about an ambitious vision brought to life. And it’s not lost on him how lucky he is to find himself in this position, the material having made its way to a passionate filmmaker and been saved the typicality of a screenplay-by-committee dismantling and re-figuring of that vision to suit, well, the suits.

“It does give me pause,” Beacham says. “I think in the process of getting it done, early on, I was just so in love with it and sort of determined to get it made one way or the other that I wasn”t thinking much about how unique the situation was, that it was an original property or that sort of thing. I was just in the zone. But it”s really sort of stunning and it”s hard to believe that it”s happened this way.”

A large part of that has been the involvement of Guillermo del Toro, who has openly said the film — in which humans face off against giant monsters called “kaiju” hellbent on taking this Earth — “saved” him at a time when he was moving from project to project, desperate for the spark of passion that would make him excited to direct a movie again. Del Toro went from “The Hobbit” to “At the Mountains of Madness” before finally saddling up to “Pacific Rim,” bringing his geeky love of kaiju adventure with him. Like Beacham (whose earliest film memory is watching a Godzilla movie), del Toro delights in the peculiarities of the genre, the world-building potential of it all.

It made for a great collaboration, the two bouncing ideas back and forth and fleshing out the universe and the backstory of a very complex concept.

“I think what was really special and really sort of unusual about the process was that everyone was kind of picturing the same movie,” Beacham says, referring also to production company Legendary Pictures, whose president Thomas Tull is a self-professed fanboy who helped launch the new Batman and Superman franchises at Warner Bros. “Nobody, from the producers to the director to the screenwriter on down had a radically different idea of what they were making, tonally and thematically. It was the same animal in all of our heads, which made the collaboration really easy.”

Some ideas that were understated in Beacham’s original draft became more pronounced when del Toro (who shares a writing credit) came on board. A sort of “Alamo feeling” was adopted, this last stand of humanity against the perpetual raging of monsters that breach our universe through a crack in the Pacific Ocean floor and wreak havoc on cities along the Pacific Rim, from Cabo to Hong Kong, San Francisco to Sydney. The character of Stacker Pentecost, played by Idris Elba in the film, took on a more authoritative role, one of highly placed military leadership rather than a more grunt-like approach (though actor Charlie Hunnam got to pick up some of the slack in that regard). And the trippy concept of “the drift,” whereby two pilots operating the massive mechs — Jaegers, as they’re called — bleed into each other’s consciousness, was carved back a bit as well.

“But it”s still part of the world, and it”s still a heavy part of the theme,” Beacham says. “And there”s one drift sequence in the movie that I think is probably, to my eyes, the best thing that I”ve ever seen Guillermo del Toro commit to film. But it”s a bit more simplified than it was in the first draft of the script. Hopefully that”s a lot of stuff that we can get into in later iterations of the story.”

In fact, the world of “Pacific Rim” is so big and the film chooses to tell such a small slice of the overall story that Beacham and company had a lot of excess “dark matter,” as he calls it, accoutrement of the universe that had to be scrapped but still boasts so much potential. The film drops the audience right into the middle of a war that has been raging between the humans and the kaiju for years, a brief prologue setting the scene. However, Beacham was given the opportunity to expand on that prequel material in the graphic novel “Pacific Rim: Tales from Year Zero.”

Beacham knew what he was wading into with the film, a subgenre of a sort that has been well-covered by movies and yearns for something new: the apocalyptic tale, the big budget, humanity-on-the-brink mayhem yarn that we’ve gotten in “Independence Day” and “Armageddon” and you name it. But Beacham’s viewpoint was that the way humans often deal with disaster in these films is from a helpless position. He wanted to tell a story that turned that convention on its head, one of aspiration rather than desperation.

“I wanted the solution to this disaster to be every bit as much of a spectacle as the disaster that they were going against,” he says. “So it wasn”t like, you know, you”re hacking into the alien”s computer or anything like that. I wanted it to be, ‘They have giant stuff, we build giant stuff.’ From the first draft of the movie there”s always been this sort of vaguely Apollo-era, big science connotation to it, which I really like.”

Indeed, to give another shade of insight into this notion, Beacham has quoted his favorite line from Ron Howard’s “Apollo 13” in the lead-up to “Pacific Rim”‘s release: “It wasn’t a miracle; we just decided to go.” But more than that, there’s a trend in Western storytelling that he wanted to buck with the film as well, one of viewing technology as something that can get out of hand and act on its own behalf. This goes back to Mary Shelley, even, but from Skynet to Marvel’s “Ultron,” technology as an obstacle has had its run.

“I think there”s a place for those sorts of stories, definitely,” Beacham says. “But I think just in terms of Hollywood movies, the ideas become so explored and so saturated that I just wanted to see something where technology was an unambiguous solution to a problem. I think we need those sorts of stories, especially in this day and time when there”s so much inherent skepticism in the populace regarding science and technology and that sort of thing. We need the other point to be made in a powerful way, I think.”

And of course, beyond the raging behemoths of “Pacific Rim,” under the hood, it had to be a story about people if an audience was going to engage. Beacham has said the Eureka moment for that came when he decided the Jaegers needed to be piloted by two neurally-connected people. How that would speak to relationships on the screen would open up countless doors. And in that idea, he even found a way into a bit of Expressionism with his script.

“I think that was what really let the story happen, because suddenly it wasn”t just about giant robots and giant monsters,” he says. “The mechs were an expression of the human drama. They were driven by the relationships of the characters. That was a real way to make the relationships of the characters important in the battles, in a literal sense.”

In the wake of “Pacific Rim,” Beacham has a lot on his plate. He’s no longer on the Disney remake of “The Black Hole” but has continued collaborating with director Joseph Kosinski as the two have charted a television series, “Ballistic City,” which was picked up by AMC. He’s also working on a sequel to “Pacific Rim,” allowing him to mine some more of that “dark matter” and expand the universe.

Beyond that, hopes are higher than ever that the first spec script he sold out of film school — a dreary fantasy called “Killing on Carnival Row” inspired by the work of author China Miéville that was a calling card for him for years — will finally go before cameras. For a time it was set to be director Tarsem Singh’s next film and del Toro has circled it in the past as well. Beacham cheekily says he wouldn’t be surprised if at some point in the near future the “Pacific Rim” director becomes involved in the project again.

For now, though, Beacham is just eager for the world to trip on the kaiju/mech disasterpiece that’s been spinning in his brain since that foggy Santa Monica morning. Tracking, intellectual properties, quadrants, these don’t concern him. What concerns him is the world he and his passionate colleagues have created, and how lucky they are to afford you passage into it.

“Pacific Rim” arrives in theaters on July 12.