Will Smith didn't just get to act opposite his son, Jaden Smith, in "After Earth" (which he also produced), the dad watched his teenage son go through a big growth spurt as the cameras rolled.
Access Hollywood caught up with the father and son duo, who are reunited again on the big screen for the first time since 2006's "The Pursuit of Happyness," at the junket for their upcoming sci-fi adventure movie - a shoot that could barely keep up with Jaden's growing body.
"I gained like 20 pounds and I grew four inches since the beginning of shooting to the end," the 14-year-old told Access.
Jaden's changing appearance was a challenge for the film's crew, including dad Will.
"[It] sucks as a producer. It's great as your father that you grew like that. As a producer of a movie... you shot something with a little kid and then a couple months later you gotta shoot some stuff with a big kid," Will explained.
Jaden' growth spurt kept the costume department busy.
"So many [costumes], I had to switch like four or five different times," he told Access.
Looking back now, Will says his son's changing appearance was beneficial to the film.
"It actually worked out because he was smaller in the beginning of the movie and we shot the ending later, so there's a there's a real cinematic value to the fact that he actually got bigger as the movie went on. You feel a sense of him mythologically growing," Will told Access.
To prep for the physically demanding role, Jaden worked hard in a variety of athletic areas.
"I did four months of training," he said. "Running, rock climbing, Parkour and swimming."
"After Earth" opens in theaters on May 31.
Copyright 2013 by NBC Universal, Inc. All rights reserved.
This material may not be published, broadcast, rewritten or redistributed.