1. A method for creating a three-dimensional movie, the method comprising: defining a depth script for a shot, wherein the depth script specifies values for each of a plurality of reference parameters, the plurality of reference parameters defining a far triangle and a near triangle associated with a stereoscopic image, the plurality of reference parameters including at least two of: a focal length for a first camera and a second camera; a far distance parameter corresponding to a distance from a plane of the first camera and the second camera to a far plane; a near distance parameter corresponding to a distance from the plane of the first camera and the second camera to a near plane; a far offset parameter corresponding to an offset distance between a left-eye point and a right-eye point in the far plane; a near offset parameter corresponding to an offset distance between a left-eye point and a right-eye point in the near plane; or a zero-plane distance parameter corresponding to a distance from the plane of the first camera and the second camera to a zero plane, wherein an offset distance between a left-eye point and a right-eye point in the zero plane is zero, wherein the value of each of the plurality of reference parameters is defined as a continuous function of time over a duration of the shot and the value of at least one of the plurality of reference parameters varies over the duration of the shot; determining, based on the reference parameter values, camera positioning parameters for the first camera and the second camera, the camera positioning parameters including an interaxial distance between the first camera and the second camera and a film-back offset for at least one of the first camera and the second camera, wherein each of the camera positioning parameters is determined as a continuous function of time over the duration of the shot and at least one of the camera positioning parameters varies over the duration of the shot; and obtaining, using the camera positioning parameters, a respective sequence of images for the shot for each of the first camera and the second camera.