Brian Wilson's fame is a complicated one. He will always be known as the driving force behind the Beach Boys, but, like many geniuses of the time, he fell prey to the pitfalls of drugs and success.

The new film Love & Mercy delves into Wilson's life during the 1960s and 1980s, each time period portrayed by Paul Dano and John Cusack, respectively. CultureMap caught up with Cusack and the director of the film on the red carpet of the U.S. premiere during SXSW.

"I think Brian, he's a genius," Cusack tells CultureMap. "So I think if you were doing a film with Mozart or Brian Wilson or Jackson Pollock or Salvador Dalí or something, you're sort of humbled by that. Because we're not geniuses. We're just people."

It's difficult to do a dramatization of someone when the subject is still alive, Cusack explains. "I think the fact that he's still here and it's his life story [is challenging]," says Cusack. "And he went to some very dark places in that period in his life."

Director Bill Pohlad says his focus was on the stories "that will be able to paint this portrait of him that people will be able to relate to, hopefully."

Love & Mercy is scheduled to be released on June 5.