Multiray: Multi-Finger Raycasting for Large Displays

We explore and evaluate a multi-finger raycasting design space that we call "multiray". Each finger projects a ray on to the display, so the user is interacting from a distance using a form of direct input. Specifically, we propose techniques, where patterns of ray intersections created by hand postures form 2D geometric shapes to trigger actions and perform direct manipulations that go beyond single-point selections. Two formative studies examine characteristics of multi-finger raycasting for different projection methods, shapes, and tasks. Based on the results of those investigations, we demonstrate a number of dynamic UI controls and operations that utilise multiray points and shapes.