Final answer:
The most interesting complex step in making the movie is the actor's process of making a choice as the character. Attending rehearsals and seeing the show grow is also a favorite part of the production process for the producer.
Step-by-step explanation:
The most interesting complex step in making the movie, as described by Ulbrich, was the process of making the actor make a choice as the character. This step added specificity and shaped the actor's performance, contributing to true storytelling. The ability to attend rehearsals and witness the show grow is also a favorite part of the production process for Hal Luftig, the producer.