Techniques for creating 3-D movies allow improved control over camera positioning parameters and editing of depth in post-process to provide for a smoother variation in the viewer's convergence distance and a more pleasant viewing experience. A director can define reference parameters related to a desired viewing experience, and camera positioning parameters are derived therefrom. A depth script specifying piecewise continuous variations in reference parameters can be applied in post-process to generate 3-D shots, scenes, or movies. These techniques can be applied in both computer-generated and live-action 3-D movies.