Spatially Augmented Reality
To create an effective illusion of virtual objects coexisting with the real world, see-through HMD-based Augmented Reality techniques supple1nent the user's view with images of virtual objects. We introduce here a new paradigm, Spatially Augmented Reality (SAR), where virtual objects are rendered directly within or on the user's physical space. A key benefit of SAR is that the user does not need to wear a head-mounted display. Instead, with the use of spatial displays, wide field of view and possibly high-resolution images of virtual objects can be integrated directly into the environ1nent. For example, the virtual objects can be realized by using digital light projectors to "paint" 2D/3D imagery onto real surfaces, or by using built-in flat panel displays. In this paper we present the rendering method used in our implementation and discuss the fundamentally different visible artifacts that arise as a result of errors in tracker measurements. Finally, we speculate about how SAR techniques might be combined with see-through AR to provide an even more compelling AR experience.