1. In a computing environment, a system comprising: one or more processors; a user interface, implemented on the one or more processors, configured to manipulate one or more parameter values associated with a stereo video scene, the user interface including an above view representation of at least part of a scene, the above view representation showing a viewer's viewpoint with respect to a screen location, the representation being interactive with respect to obtaining input for manipulating the one or more parameter values, the user interface further configured to provide a selection to lock together one or more different types of parameter values to create a stereoscopic effect, such that changing one parameter value changes the one or more different types of parameter values locked together with the one parameter value; and a timing control mechanism configured to control operations of blending vergence values before and after a cut or changing the vergence values to draw attention to an object in the scene.