An Approach to Maintaining Viewer Perspective in Interactive Virtual Tours Thomas Carpenter, Gregory Doerfler, Thomas Way and Frank Klassner Center of Excellence in Enterprise Technology Department of Computing Sciences Villanova University, Villanova PA 19085 thomas.way@villanova.edu Abstract - While virtual tours have been around for some time, the ability to get a true sense of the location has not been adequately developed. As part of a partnership between our department and the Vatican, we have created a virtual tour of the Sistine Chapel using multiple locations and interactive menus to allow users to feel as though they are actually there. Not only does the virtual tour give users a true sense of the place, but also it offers information about the chapel as well as the biblical history of paintings on the wall. The innovative aspect of this tour is the degree of attention given to maintaining viewer perspective at all times, so that movement appears both smooth and intuitive. In this paper, we discuss the overall development process of this virtual tour, and focus on the perspective maintaining techniques that were devised and evaluated. Keywords: Virtual Tour, Virtual Reality, Perspective, Stitcher, Krpano, XML. 1 Introduction As part of an ongoing partnership between our home institution department and the Vatican, we created a virtual tour of the Sistine Chapel. This undertaking was a follow-up to a Vatican internship and study abroad experience in Rome during the fall semester of the junior year of a two student team (Carpenter and Doerfler). As a part of the internship, the team assisted Villanova research faculty with photographic shoots at various locations in and around the Vatican. The most notable location was the well-known and highly recognizable Sistine Chapel. At these photographic shoots, a special camera and rotating stand were used to take hundreds of images in the complete 360° panoramic range of directions from a central, fixed location, or in the case of the Sistine Chapel which has a central half-wall that does not make a single location practical, two fixed locations. Once the photographic images data was gathered, the images were digital “stitched” together into a seamless, 360° panoramic view. To perform this image concatenation, a software program called Stitcher Unlimited was used. Stitcher Unlimited (stitcher.realviz.com) was used to stitch together the images from the Sistine Chapel into two panoramas, each centered on a fixed point within one of the two sides of the Chapel. These panoramas were then edited to remove minor imperfections in the stitching and developed further using the interactive 3D panorama viewing system and scripting language, Krpano (krpano.com). The result of this extensive development effort was the production of a 3D interactive tour that incorporates context-sensitive menus, visual and contextual “hotspots” and an intuitive navigation system. This combination of features and functionality, together with the innovative perspective maintaining panning algorithm we devised and the uniqueness of the Sistine Chapel as a setting, potentially marks this project as a significant contribution to the field of virtual tours. 2 Virtual Tours Virtual tours work by offering a location (an axis point) from which the user can “look around” – changing the perspective, rotating the camera, and adjusting the zoom. Clickable “hotspots” link two or more locations together and allow the user to move to the next location. What makes a virtual tour a tour of some location and not simply a single-location panorama is this ability to transport from one specific location to another within the boarder context of the location being virtually visited. In this project, a novel algorithm was devised that determines the visually “best,” or most intuitive and visually pleasing, path when moving from specific