One of the many things that Gunn speaks about on the podcast was Vin Diesel playing the character of Groot in the film. Fans noticed last week that we got a taste of Bradley Cooper's voice as Rocket Raccoon in the character introduction video, but not a tease of Diesel's line as the Monarch of Planet X, but Gunn teased the variations of his lines saying: "The ways in which Vin Diesel says 'I am Groot,' I am astounded."
Gunn went on to reveal that others had provided the voice for Groot during the production of the film, but says none of them felt right until Diesel came aboard.
"All of the 'I am Groots' that were earlier voices didn't sound very good at all, they sounded like sh*t. It just didn't really work. Then Vin came in and in one day, laid down all these 'I am Groot' tracks, and he's a perfectionist. He made me explain to him with ever 'I am Groot,' exactly what he was saying.....Then Vin would sit there and he would do it and he would it again and again and again, and his voice is so rich and so beautiful and he really opened up and was this character. It was amazing when we first put that voice in there how much the character changed and how much he influenced the character."
When asked about Vin performing motion capture for the character in the film, Gunn replied:
"We're doing some mo-cap. What we're doing basically with Bradley, and my brother Shaun, and with Vin Diesel, we film everything that they do so we can use it as a reference. So while they're recording in front of a microphone we'll have Vin acting out everything and doing all the acting and we'll record that."
Guardians of the Galaxy features an unlikely cast of characters who must team up in order to defeat a cosmic force of epic proportions. The August 1 release stars Chris Pratt, Zoe Saldana, Dave Bautista, Lee Pace, Michael Rooker, Karen Gillan, Djimon Hounsou, Benicio del Toro, John C. Reilly, Glenn Close, Gregg Henry, Bradley Cooper and Vin Diesel.