'The Imaginarium of Doctor Parnassus' Director on Heath: Generous, Sweet, Brilliant

At the NYC premiere of The Imaginarium of Doctor Parnassus on Monday, celebrities remembered the film's fallen star, Heath Ledger. Director Terry Gilliam and actress Lily Cole reminisced with reporters about what it was like working with Heath on what turned out to be his last movie.

Lily, who plays Valentina in the film, remembered the highs and lows of filming the movie.

"It was really good, we had a lot of extreme highs, extreme lows, Lily told OK! "It was really interesting to work with such creative people for a long period of time."

"He was such a special, generous and creative individual," Lily continued. "I am very lucky to have met him."

Director and writer Terry could describe Heath in three words.

"Generous, sweet, brilliant," he said. "He was a genius."

Terry couldn't choose just one actor to take on Heath's role.

"There was no way one person would replace Heath," he explained. "I couldn’t think of a person good enough to do that. Luckily, his characters goes through this magic mirror three times, bingo!"

Johnny Depp, Jude Law and Colin Farrell took on Heath's role, but Heath was very different from them.

"He’s taller than some of them. Taller than the three of those guys," Terry said. "He was just brilliant and he was so grounded, however outrageous I was pushing him in situations, he was always grounded, there was weight, there was gravity, no matter how playful he was. He was getting better and better. And he’s gone."

For Lily, having three new actors like Johnny, Jude and Colin fill Heath's place was an intense experience.

"I found it very touching in a very emotional time," she told reporters. "It was a really wonderful gesture they made."

The three actors donated all their money to Heath's daughter Matilda, which Terry said they did by their own choosing.

"Obviously Heath didn’t finish the part, and the insurance company was not going to pay his family for what he had done and they said, 'Ridiculous. We’ll take over, we’ll do it and the money meant to be paid will go.'”

Terry told OK! that he thinks this movie will mean a lot to Heath's family.

"I think obviously we were delighted when we found a way that his final role is finished," he told OK! "I think they must be utterly overwhelmed by the fact that so many people came forward to finish the job.  I think it has been very very difficult for them."

And what would Heath say if he were here today?

"That’s the thing I liked about Heath," Terry said. "I could never tell… But I think he’d be happy."

Reporting by Jessica Summers