HOLLYWOOD, CA—It wasn't easy, and it took a lot of work, but in the end it sounds like it was worth it.

When the producers of The Fast and the Furious franchise considered whether or not to make an eighth film, they had to weigh the pros and the cons. Was it right? Was it moral? Was it even possible?

And moreover, would they be able to use modern technology to ensure that series star Vin Diesel still seemed like he looked, spoke, and moved like a regular person?

This was seen as the biggest challenge of all.

F. Gary Gray, director of the new instalment entitled Fate of the Furious, or F8 of the Furious, says that he never thought the task would be easy, and indeed it was not.

"There were obviously glitches, as you might expect," says the director.

"You know, Vin would say a line and I would have to stop the shoot and say, okay everybody, that did not sound like the way a real human being would speak. And so we'd try again."

"We'd prep him and warm him up and send him out there again. We never gave up on trying to make Vin seem at least semi-realistic. People have to believe they're looking at a real person, even if they're just looking at Vin Diesel."

Co-star Dwayne Johnson remained characteristically positive about the challenges of acting alongside something like Diesel.

"Obviously I'm doing a lot of the work there, but it's fun," said the former professional wrestler.

"Certainly it's not like working with an actor. You can't count on his eye-line matching up with yours, though they fix a lot of that in post."

"And in the fight scenes, I imagine they had to do a lot of work there, speeding him up to get him to move at the same rate a human would. But I had a hell of a time and I think it's a hell of a movie, and when people look at Vin I honestly think they'll barely be able to tell a different between him and a normal person acting in a movie. Barely."

At press time, producers were working on an updated model of Diesel for the next edition, tentatively titled The Fast & T9he Furious.