Prior to his role in Transformers 4: Age of Extinction, Mark Wahlberg underwent computer-generated imagery (CGI) training in his previous movie, Ted.  CGI is an advanced video technology that enables actors to simulate interaction with computer-generated figures as it would appear in real life.

"Ted' was definitely a good warm up," Wahlberg said.

"With 'Ted,' it was a more intimate setting. But this movie is much bigger and more intense," said Wahlberg in an interview with Los Angeles Times' Hero Complex. 

He admitted that one of the biggest challenges in working with CGI-based films is the actors trying to avoid looking awkward or unnatural while shooting.  In reality, they are talking to mere inanimate objects on set, but they obviously must maintain the realistic drama and interaction with the CGI generated character.

Wahlberg, 42, added, "You've got eight Autobots talking to you at the same time. There's nothing but a pole or a stick really there," he admitted. "You've got to believe and totally commit. The most difficult part of acting is when you look ridiculous and have to confront the risk of looking foolish. You've got to be on the whole time. You can't phone it in."

Aside from his CGI familiarization, the Cade Yeager actor went into serious body workout which had him lose a total of 60 pounds in preparation for the role. 

"I had to come back for some pick-up shots.  So when Bay saw me, he freaked. He was used to seeing me on the healthier side.  But here I am skinny with long, stringy hair.  He was like, 'You can't look like that!'"

The Boston native actor emphasized that while people may think that this is a fourth film following from the original Transformers trilogy, in fact the Extinction is to a large extent a stand alone film.  So far, all the other Transformers movies earned $3 billion globally.

Transformers 4: Age of Extinction will be shown in theaters on June 27.