Shadow-free Interaction: A Proposal for Rear Projection Based Shape Display

In this research, a shape display is developed which renders 3D shapes and textures by actuator arrays and projectors. Generally, a shape display has a feature that users can interact with it by their hands directly. Textures on the surface of a shape display are projected by a projector installed above the shape display. However, this composition casts shadows on the shape display when a user interacts with it and users cannot interact with it correctly due to this shadow problem. In this paper, we describe the development and validation of a shape display that avoids casting shadows by applying rear multi-projection.