IF filmmaking is a war, then “Apocalypse Now” was very nearly Francis Ford Coppola’s Waterloo.

The battles Coppola fought while making his 1979 epic nearly destroyed him. A typhoon wrecked a major set. Harvey Keitel was replaced by Martin Sheen. Coppola searched desperately for an ending. He worked even harder to coax a few lines out of Marlon Brando.

But out of that tumult Coppola created a masterpiece. And 40 years later, “Apocalypse Now” has never looked so good.

Coppola has supervised a 4K restoration of the film and, for the second time, tweaked the cut. Having perhaps gone too far in his 2001 “Redux,” which added 53 minutes, “Apocalypse Now Final Cut,” splits the difference at 183 minutes.

In its present and restored form, the majesty and madness of “Apocalypse Now” is more vivid and hallucinatory than ever. Coppola considers it the definitive version.

Coppola, 80, has been busy with equally audacious plans.

In 2017, he published a book, “Live Cinema and its Techniques,” about his experiments and hopes for a new art form that combines cinema, television and theater in a live experience. He’s also recently returned to a long delayed passion project, “Megalopolis,” a sprawling sci-fi, New York-set epic. Coppola has been working on the script and casting, and searching for production partners.

“Or maybe now it’s at the stage I can do it by myself, I don’t know,” he said.

In a recent interview, Coppola spoke about “Apocalypse Now” then and now, why he was “terrified” after making it and why he has so much trouble letting go.

Q: You’ve talked before about the theatrical version of “Apocalypse Now” missing some of the “weirdness” you wanted. What did you mean?

A: In the 1979 version, the various people who had sponsored it and were distributing it felt that it was too long and too weird. So we took some things out. After I was looking at it on television and it stuck out less as something unusual. For that reason, people kept saying to me, “Maybe you should have put back what you took out.”

Q: Did you consciously want to put your stamp on the war movie?

A: The Vietnam War was different than other American wars. It was a West Coast sensibility rather than an East Coast sensibility. In war movies before “Apocalypse,” there was always a sort of Brooklyn character, an East Coast and Midwest personality. In “Apocalypse Now,” it was LA and it was surfing and it was drugs and it was rock ‘n’ roll so it was more of a West Coast ambiance to the war. In addition, there were many sort of odd contradictions that related to the morality involved.

Q: You’ve gone back and made changes to a number of your films. For you, is a film ever really finished?

A: The only reason I’m in a position to go back and evaluate some of these decisions is because I own the film. The version that you open with, you’re very concerned, because a film that opens with a negative reception is dead. If you look at all the films I made, only “The Godfather” was just a runaway creative hit. Most of the other films were highly qualified and that meant that I was trying to nurse them into surviving.

Q: Eleanor Coppola, your wife, wrote in her “Notes” that you took on some of Kurtz’ megalomania while making “Apocalypse Now.”

A: Whenever I made a movie, I was always personally compared to the main character. When I was doing “The Godfather,” I was Michael Corleone, Machiavellian and sly. When I made “Apocalypse Now,” I was the megalomaniac. When I made “Tucker,” I was the innovative entrepreneur. The truth of the matter is all my life if I have been anything I’ve been enthusiastic and imaginative.

Q: A recent Film Comment essay lamented the film’s portrayal of Vietnam as “a spectacular but soulless backdrop.”

A: It would have been interesting and good if the movie had been made in Vietnam. But the truth of the matter is when we were making “Apocalypse Now,” the Vietnamese War was only winding down. We did not have access. We were making it in the Philippines. And this film was specifically about these young California Americans participating in this war, and that was the lens it was made through.

Q: Did you emerge from “Apocalypse Now” a different filmmaker?

A: Yeah, but no more than I was after the extreme experience of the “Godfather” movie. Every film I have made has been a new sheet of paper. I rarely would repeat a style. Every movie I worked on, I came out of it being a different person.

Q: How did you feel after “Apocalypse Now”?

A: I was terrified. For one thing, I was on the hook for the whole budget personally — that’s why I came to own it. In addition, in those days interest was 25 percent to 27 percent. So it looked as though, especially articles labelling it “the heralded mess” of the year, I was never going to get out of the jeopardy I was in. I had kids, I was young. I had no family fortune behind me. I was scared stiff. It was no different after “Godfather.” “Godfather” was a project I was constantly about to be fired from. I’m 80 now but from age 25 to 60, my life was one crisis after another.

Q: Do you think you thrive in that kind of tumultuous environment?

A: When you attempt something that you don’t exactly know how to do but you still long to attempt it, you’re setting the stage for a certain style and struggle in life. Clearly if after I made the gangster movie that was successful, if I had just spent my entire career making gangster pictures, that would have been a more tranquil life. I wanted to learn. I realize now that one of my fundamental aspirations is learning. There’s nothing more pleasurable than learning something you don’t know how to do.

Q: Is going back to your films to get them just right for you part of preserving your legacy? Do you think about how you want you and your work to be remembered?

A: I’m not so crazy about my legacy. I want people to know that I was a good camp counselor in 1957, that I have a family with wonderful children. But ultimately, to me, the greatest legacy you can have is that someone somewhere saw one of the things you did and it inspired them to do something that goes and then inspired someone else in the future. In a way, it’s a form of immortality.

Q: Today, most directors seeking the scale of “Apocalypse Now” would likely only find it in a superhero film. Do you sympathize with them?

A: Absolutely. I feel now we have this bifurcated cinema in our country being of independent films where we have the most wonderful wealth of talent and then the industry films which are pretty much superhero films. One has too much money — the studio, Marvel comic-type movies. They’re basically making the same movie over and over again, and seducing all of the talent. And as opposed, the wonderful, unusual, exotic, interesting, provocative and beautiful independent films have no money.

Q: The long life your films have had can lead to strange places. Donald Trump has cited it as one of his favorite films.

A: The list of fans of the “Godfather” films not only includes the gentleman you speak of but also Saddam Hussein and Gaddafi. Just go through all of the toughest dictators in the modern world and their favorite movie is “The Godfather.”

Q: What do you make of that?

A: Because “The Godfather” is an American story of an immigrant family that ultimately finds success in America. Success is not a bad thing but it depends on how you define it. If you define success as wealth, influence, power and fame, you have to know that does not bring happiness. What brings happiness is friendship, learning, creativity. We know what brings happiness. But what are you going to do when every nation in the world is pointing its main objective toward something that does not add up?