By placing “motion objects” in a three-dimensional space, interactive videos can be easily produced. By managing both the walk-through images and the motion objects inside the three-dimensional space, and also by synthesizing the displayed video according to the user’s location and actions, the system enables a more natural synthesized video experience to be created. In this paper, we propose a new video system framework called Videoplex for a videobased application that realizes both free movement of the user’s viewpoint and object motion independent of viewpoint movement.