The documentary is narrated by British movie star Orlando Bloom.
Trumbull was adamant he wanted Bloom and no one else for his project.
"I had decided that I really wanted him to narrate my film
for I love his voice - it is very powerful and commanding
and so I was determined to somehow make it happen," he says.
"I tracked down and found his agent's contact information
and then I sent her an email.
I wasn't sure if she was going respond at all."
Unfortunately, Bloom was filming the third in
the Pirates of the Caribbean series at the time.
But Trumbull did not give up.
"I believe that Orlando was always very much into narrating the film,
but it was just a matter of his schedule and so after a lot of backs
and forths with his agent, and excitement and patience on my part,
they agreed to make it happen and to fit it into his schedule
whenever he could.
All in all, it took about a year to make it happen,
but it was definitely worth the wait.
I met and directed him in a studio in Hollywood.
Orlando was a wonderful guy, completely genuine and incredibly nice,
and his voice was perfect for the film. I could not be happier.
I feel extremely fortunate and blessed that it all came together."