How is heath ledger in the imaginarium of doctor parnus?

He died half-way through filming it. I saw an interview with the director and he said that Johnny Depp, who is also in the movie, kind of rallied everyone and kept everyone focused after losing Heath Ledger. I'm not completely sure what the movie is about, but I know that Heath Ledger's character is also portrayed as 3 "imaginarium characters" too, and those are played by Johnny Depp, Colin Farrell, and Jude Law, so I ume that they finished filming Heath Ledger's part before he died.