A Movie Pipeline Executor is responsible for executing an array of Movie Pipelines, and (optionally) reporting progress back for the movie pipelines. The entire array is passed at once to allow the implementations to choose how to split up the work.Bydefault we provide a local execution (UMoviePipelineLocalExecutor) which works on them serially, but you can create an implementation of this class, change the default in the Project Settings and use your own distribution logic. For example, you may want to distribute the work to multiple computers over a network, which may involve running command line options on each machine to sync the latest content from the project before the execution starts.