Speaking to the Los Angeles Times, Branagh admitted that he was initially sceptical about the conversion before coming around to the belief that 3D "could be the very good friend of story and character for a different kind of experience".
Branagh said: "It's another draft of the story that can reveal itself in a different way I had a healthy degree of scepticism up front... I've become somebody extremely excited about working with possibilities of doing it this way."
Captain America helmer Joe Johnston also voiced his reservations about the format, although he called the process "a new challenge and exciting".
"I think [3D] tends to be overused and can be a little bit gimmicky," Johnston explained. "A lot of people are using 3D now because they feel have they have to... that will come and go and the pictures that deserve to be in 3D will continue to be. When it's done bad, it can make you carsick."
Thor, Marvel's first 3D release, opens in cinemas in May 2011, while Captain America follows in July.