Film production involves a complex set of processes that balance aesthetic, financial, and organizational needs. These processes have changed over time: some changes have arisen in response to the different kinds of film that have dominated various industrial eras; some have arisen from the changing shape of industrial organization; and others are a function of the ways in which technology has evolved. Yet even in the present day, filmmaking practices used to create different types of film can vary greatly. The production processes of a live-action film and an animated film, for instance, will differ substantially. Nevertheless, the main stages through which production moves are normally clearly identifiable regardless of the type of film involved. This process is conventionally divided into four parts: development, which deals with conceiving, planning, and financing the film project; preproduction, when key resources such as cast, crew, and sets are assembled and prepared; principal photography, during which time the film is actually shot; and postproduction, which involves editing the raw footage and adding the visual effects and soundtrack.