George Miller, director of Mad Max: Fury Road, says he is "heartbroken" over the personal plight of Mel Gibson - the star of the original 1979 movie and its subsquent sequels. Miller picked Tom Hardy to lead the fourth film of the post-apocalyptic action franchise though has sympathy for Gibson, whom he describes as a "wonderful actor."

Mad Max Tom HardyTom Hardy replaced Mel Gibson as Mad Max

"I have a great affection for Mel. I was really heartbroken to see him go into that," Miller said in a recent interview.

"But it's a new time. I hope Mel gets to act in more movies because I think he's a wonderful actor. But I think he's an amazingly good director."

More: Why 2014/2015 could be Tom Hardy's time to shine

The 69-year-old director was instrumental in launching Gibson's career three decades ago and Miller had originally hoped to bring back the actor for a fourth outing as Max Rockatansky, being opting for Hardy.

Tom Hardy Mad MaxPretty cool huh?

Miller describes Fury Road as an extended car chase taking place over three days. The movie, due out next May, co-stars Charlize Theron and features very little dialogue. The screenplay merely consisted of sketches and storyboards, rather than the conventional script.

More: check out our Mel Gibson interview

"You're picking up the characters and the backstory as you go," Miller said. "And in order to create that backstory, we found ourselves having written two other screenplays. One of them is completed. The other one is in the form of a kind of unedited novel. So by the time we got there, we realised we've got a couple more Mad Max stories to tell, and that ... required us to cast someone who was younger."

Miller showed footage from Mad Max: Fury Road at the recent Comic-Con International in San Diego.

Watch the first trailer for Mad Max: Fury Road: