A user interface may be presented to a user that may provide an intuitive interface configured for generating animations. The user interface may be users of varying levels of expertise, while retaining the freedom of authoring complex narratives in an animation. A given narrative may be constrained by user input related to one or more of events to occur in an animation, individual animation components that may be included in the events, and/or other input. The system may be configured to “fill in” missing gaps in a narrative to generate a consistent animation while still meeting one or more narrative constraints specified by user input. By way of non-limiting example, gaps may be “filled in” by effectuating non-user selections of one or more of events, animation components, and/or other information used to generate an animation.