This paper investigates the use of Spatial Augmented Reality in the prototyping of new human-machine interfaces, such as control panels or car dashboards. The prototyping system uses projectors to present the visual appearance of controls onto a mock-up of a product. Finger tracking is employed to allow real-time interactions with the controls. This technology can be used to quickly and inexpensively create and evaluate interface prototypes for devices. In the past, evaluating a prototype involved constructing a physical model of the device with working components such as buttons. We have conducted a user study to compare these two methods of prototyping and to validate the use of spatial augmented reality for rapid iterative interface prototyping. Participants of the study were required to press pairs of buttons in sequence and interaction times were measured. The results indicate that while slower, users can interact naturally with projected control panels. |