Movement through multi-dimensional space is simulated using a series of panoramic images which are projected or displayed in sequence. The user's direction of view, that is the selected view window, is maintained as the series of images is projected or displayed. Motion in directions other than forward or reverse is simulated by utilizing "
branch" points in the sequence. Each path from a
branch point simulates motion in a different direction.
Branch points are generally indicated to a viewer by visual indicators called "hot spots"; however,
branch points may also be hidden and activated in response to the viewer's selected direction of view. If a branch point is indicated by a visual indicator, a user can select motion in a desired direction by clicking on a "hot spot".In order to conserve storage space, the image representing each
panorama can be stored in a compressed format. Only the portion of the
panorama necessary to create a "view window" that is, the portion of the image displayed in response to the user's direction of view, is decompressed at view time. An index methodology is used to store the panoramic images. Use of the indexing methodology allows the images to be retrieved in both the forward and backward direction to simulate movement in either direction. Sound is provided in a special format, so that
special effects can be provided based on the user's point of view and dependent upon the direction of motion selected by the user.