Complex sentence: Fellini based some of the characters on a real prostitute whom he had met while filming "Il Bidone" and for authenticity, he had Pier Paolo Pasolini, known for his familiarity with Rome's criminal underworld, help with the dialogue.
Split into simpler sentences: Fellini based some of the characters on a real prostitute whom he had met while filming "Il Bidone". For authenticity, he had Pier Paolo Pasolini, known for his familiarity with Rome's criminal underworld, help with the dialogue.